`PUT /omicron-physical-disks` timeout on rack3

Today while investigating an issue with a different sled, we briefly enabled the blueprint_executor task. PUT /omicron-physical-disks requests to sled 13 (BRM42220064) were consistently timing out after 60 seconds. The sled-agent log is at /staff/rack3/BRM42220064/2024-10-18/oxide-sled-agent-default.log. We see the dropshot "client disconnected" logs from client timeouts that are consistent with the 60sec timeout error we were seeing from Nexus, like:

john@jeeves /staff/rack3/BRM42220064/2024-10-18 $ grep '\[fd00:1122:3344:10e::3\]:35457' oxide-sled-agent-default.log  | looker
21:26:54.440Z INFO SledAgent (dropshot (SledAgent)): accepted connection
    file = /home/build/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dropshot-0.12.0/src/server.rs:1105
    local_addr = [fd00:1122:3344:104::1]:12345
    remote_addr = [fd00:1122:3344:10e::3]:35457
21:27:54.483Z WARN SledAgent (dropshot (SledAgent)): request handling cancelled (client disconnected)
    file = /home/build/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dropshot-0.12.0/src/server.rs:887
    latency_us = 60040091
    local_addr = [fd00:1122:3344:104::1]:12345
    method = PUT
    remote_addr = [fd00:1122:3344:10e::3]:35457
    req_id = efaaabcd-36eb-49e2-881c-4de2f7b08340
    uri = /omicron-physical-disks

Start with the sled-agent log at /staff/rack3/BRM42220064/2024-10-18/oxide-sled-agent-default.log and trace the PUT /omicron-physical-disks request, including the period when blueprint_executor was enabled. Confirm where the 60-second delay occurs and document or fix the cause so the request no longer times out; validate the behavior against the reported sled case.