test: allow sub-second poll time

[brice-stacks]

I don't think there is any downside to setting this to zero for tests and it should give us some speedup.

Zero does not allow enough time for other threads. The second commit here allows sub-second poll time and defaults to 100ms.

[coveralls]

Coverage Report for CI Build 24271162921

Coverage decreased (-0.07%) to 85.644%

Details

• Coverage decreased (-0.07%) from the base build.
• Patch coverage: 18 of 18 lines across 3 files are fully covered (100%).
• 1960 coverage regressions across 70 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

1960 previously-covered lines in 70 files lost coverage.

Top 10 Files by Coverage Loss	Lines Losing Coverage	Coverage
stackslib/src/net/inv/epoch2x.rs	221	79.49%
stackslib/src/net/chat.rs	199	93.0%
stacks-node/src/nakamoto_node/miner.rs	137	86.85%
stackslib/src/net/api/postblock_proposal.rs	107	82.16%
stackslib/src/clarity_vm/database/marf.rs	99	60.67%
stackslib/src/net/p2p.rs	79	73.82%
clarity/src/vm/contexts.rs	75	92.36%
clarity/src/vm/functions/database.rs	75	92.36%
stackslib/src/net/codec.rs	69	91.63%
stackslib/src/clarity_vm/database/ephemeral.rs	61	56.82%

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Coverage Stats

Relevant Lines:	217895
Covered Lines:	186613
Line Coverage:	85.64%
Coverage Strength:	17347657.66 hits per line

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💛 - Coveralls