unittest/wallet/test/run-chain_moves_duplicate-detect: fatal_vfmt called!

Configured v25.09.1 with:
```
./configure --prefix=/usr --disable-debugbuild --disable-compat --disable-valgrind \
--disable-static --disable-coverage --disable-address-sanitizer --disable-ub-sanitize \
--disable-fuzzing --disable-rust
```

During `make check-units`:
```
BOLTDIR=.tmp.lightningrfc wallet/test/run-chain_moves_duplicate-detect > /dev/null
fatal_vfmt called!
```

Unfortunately, no stack trace is printed. I may be able to get one with GDB if the cause is not immediately known.

This was on a PostgreSQL-only build (no SQLite). **The test passed on a SQLite-enabled build.**