fix: worker: listen for interrupt signals in GetStorageMinerAPI loop

[rjan90]

Proposed Changes

Listen for interrupt signals in GetStorageMinerAPI loop, allowing for graceful shutdown in case the worker is brought up before the lotus-miner process is running.

Additional Info

Before:

lotus-worker run
2023-10-03T04:19:52.209-0400    INFO    main    lotus-worker/main.go:296        Starting lotus worker
Connecting to miner API... (RPC client error: sendRequest failed: Post "http://10.2.2.22:2345/rpc/v0": context canceled)
Connecting to miner API... (RPC client error: sendRequest failed: Post "http://10.2.2.22:2345/rpc/v0": context canceled)
Connecting to miner API... (RPC client error: sendRequest failed: Post "http://10.2.2.22:2345/rpc/v0": context canceled)^C^C^C
Connecting to miner API... (RPC client error: sendRequest failed: Post "http://10.2.2.22:2345/rpc/v0": context canceled)^C

After:

lotus-worker run
2023-10-03T05:51:09.475-0400    INFO    main    lotus-worker/main.go:297        Starting lotus worker
Connecting to miner API... (RPC client error: sendRequest failed: Post "http://127.0.0.1:2345/rpc/v0": dial tcp 127.0.0.1:2345: connect: connection refused)^C2023-10-03T05:51:10.343-0400       WARN    main    lotus-worker/main.go:115 Interrupted by user:
    main.glob..func6
        /root/lotus/cmd/lotus-worker/main.go:352

Checklist

Before you mark the PR ready for review, please make sure that:

• Commits have a clear commit message.
• PR title is in the form of of <PR type>: <area>: <change being made>
  • example: fix: mempool: Introduce a cache for valid signatures
  • PR type: fix, feat, build, chore, ci, docs, perf, refactor, revert, style, test
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• Tests exist for new functionality or change in behavior
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[Stebalien]

We should be able to drop this.

(also, this will re-assign cancel, leading to a data race with the goroutine above)

[rjan90]

I dropped this here: f759f4d

[Stebalien]

One nit, otherwise LGTM. Sorry for the delay, I didn't notice your changes. Feel free to bug me on slack if I'm not responsive.

[Stebalien]

Eh, I just removed the offending line.