pay: infinite pay loop

Found on regtest with cln v25.02.
There is a too high cltv delay. The payment appears to do many many attempts rather than giving up immediately.

```
lightningd-3 2025-03-18T12:32:59.824Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Received getchaininfo blockcount=116, headercount=116
lightningd-3 2025-03-18T12:32:59.825Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: waitblockheight reports syncheight=116
lightningd-3 2025-03-18T12:32:59.825Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Updated a channel hint for 103x1x0/1: enabled true, estimated capacity 985709000msat
lightningd-3 2025-03-18T12:32:59.825Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Updated a channel hint for 13828588x5499551x11099/1: enabled false, estimated capacity 0msat
lightningd-3 2025-03-18T12:32:59.826Z DEBUG plugin-pay: Received a channel_hint {.scid = 103x1x0/1, .enabled = 1, .estimate = 985709000msat, .capacity = 1000000000msat }
lightningd-3 2025-03-18T12:32:59.826Z DEBUG plugin-pay: Received a channel_hint {.scid = 13828588x5499551x11099/1, .enabled = 0, .estimate = 0msat, .capacity = 1000000000msat }
lightningd-3 2025-03-18T12:32:59.826Z INFO plugin-pay: cmd 1/cln:pay#172 partid 0: Filtering out 1 routehints
lightningd-3 2025-03-18T12:32:59.827Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:32:59.827Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: After filtering routehints we're left with 1 usable hints
lightningd-3 2025-03-18T12:32:59.827Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:32:59.827Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Using routehint 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59 (110x1x0) cltv_delta=18
lightningd-3 2025-03-18T12:32:59.827Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: The destination is directly reachable including attempts without routehints
lightningd-3 2025-03-18T12:32:59.828Z INFO plugin-pay: cmd 1/cln:pay#172 partid 0: Initial limit on max HTLCs: 15, Destination 0266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c03518 has 1 channels, assuming 15 HTLCs per channel
lightningd-3 2025-03-18T12:32:59.828Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:32:59.828Z INFO plugin-pay: cmd 1/cln:pay#172 partid 0: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:32:59.828Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 0: Retrying 78dc9a033bb09f7aafb35d3e769d88f8d45b29a88036d9416c7b7fc73f32199e/0 (100000000msat), new partid 1. 9 attempts left\n
lightningd-3 2025-03-18T12:32:59.829Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 1: Not using a routehint
lightningd-3 2025-03-18T12:32:59.829Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 1: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:32:59.829Z INFO plugin-pay: cmd 1/cln:pay#172 partid 1: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:32:59.829Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 1: Adaptively split into 2 sub-payments: new partid 2 (51234785msat), new partid 3 (48765215msat)
lightningd-3 2025-03-18T12:32:59.830Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 2: Not using a routehint
lightningd-3 2025-03-18T12:32:59.830Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 2: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:32:59.830Z INFO plugin-pay: cmd 1/cln:pay#172 partid 2: CLTV delay exceeds our CLTV budget: 46 > 45

... (etc. etc. moving on to partid 5787)

lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5787: Not using a routehint
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5787: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5787: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5787: Lower limit of adaptive splitter reached (51783msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5789: Using routehint 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59 (110x1x0) cltv_delta=18
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5789: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5789: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5789: Lower limit of adaptive splitter reached (55444msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5790: Not using a routehint
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5790: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5790: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5790: Lower limit of adaptive splitter reached (66135msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5792: Not using a routehint
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5792: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5792: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5792: Lower limit of adaptive splitter reached (55497msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5794: Using routehint 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59 (110x1x0) cltv_delta=18
lightningd-3 2025-03-18T12:33:05.461Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5794: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5794: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.461Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5794: Lower limit of adaptive splitter reached (57422msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.462Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5795: Using routehint 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59 (110x1x0) cltv_delta=18
lightningd-3 2025-03-18T12:33:05.462Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5795: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.462Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5795: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.462Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5795: Lower limit of adaptive splitter reached (56763msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.467Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5796: Not using a routehint
lightningd-3 2025-03-18T12:33:05.467Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5796: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.467Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5796: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.467Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5796: Lower limit of adaptive splitter reached (60329msat < 100000msat), not splitting further.
lightningd-3 2025-03-18T12:33:05.467Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5797: Not using a routehint
lightningd-3 2025-03-18T12:33:05.467Z DEBUG plugin-pay: cmd 1/cln:pay#172 partid 5797: Checking hint {.scid=103x1x0/1, .enabled=1, .estimate=985709000msat}
lightningd-3 2025-03-18T12:33:05.467Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5797: CLTV delay exceeds our CLTV budget: 46 > 45
lightningd-3 2025-03-18T12:33:05.467Z INFO plugin-pay: cmd 1/cln:pay#172 partid 5797: Lower limit of adaptive splitter reached (50381msat < 100000msat), not splitting further.
```