fix: Change timeouts to fix flaky tests miner_stackerdb_version_rollover and multiple_miners_mock_sign_epoch_25

[jbencin-stacks]

Description

Fix flaky tests I observed while working on #6981:

• wait_for_registered: Change sleep() and send_status_request() args to match other tests
• multiple_miners_mock_sign_epoch_25: Increase timeout to match boot_to_epoch_3

Additional info (benefits, drawbacks, caveats)

It's hard to know if this change will solve the flakiness 100%, it's basically applying patterns from non-flaky tests and previously fixed flaky tests

Checklist

• Changelog fragment(s) or "no changelog" label added (see changelog.d/README.md)
• Run each test 10 times locally to test. No failures

[brice-stacks]

👍

[coveralls]

Coverage Report for CI Build 24255616294

Coverage decreased (-0.04%) to 85.673%

Details

• Coverage decreased (-0.04%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 1886 coverage regressions across 63 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

1886 previously-covered lines in 63 files lost coverage.

Top 10 Files by Coverage Loss	Lines Losing Coverage	Coverage
stackslib/src/net/inv/epoch2x.rs	214	79.84%
stackslib/src/net/chat.rs	205	92.87%
stacks-node/src/nakamoto_node/miner.rs	134	87.08%
stackslib/src/net/api/postblock_proposal.rs	102	82.89%
stackslib/src/clarity_vm/database/marf.rs	99	60.67%
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/net/p2p.rs	65	75.09%
stackslib/src/clarity_vm/database/ephemeral.rs	61	56.82%

---

Coverage Stats

Relevant Lines:	217886
Covered Lines:	186670
Line Coverage:	85.67%
Coverage Strength:	17064302.84 hits per line

---

💛 - Coveralls

[francesco-stacks]

Changes look fine, but the test multiple_miners_mock_sign_epoch_25 is still failing, could also bump

stacks-core/stacks-node/src/tests/signer/mod.rs

Line 494 in 93d9c4e

wait_for(120, || {

to 240 secs? seems this is the place where it is now failing