Reduce test flakiness in CI

[pavitthrap]

Description

I'm attempting to lower the flakiness by adding some sleep statements in the following three tests:

• test_problematic_microblocks_are_not_relayed_or_stored
• epoch_23::trait_invocation_behavior
• epoch_22: pox_2_unlock_all

[codecov]

Codecov Report

Merging #3743 (b57741e) into develop (7a0e572) will decrease coverage by 0.23%.
The diff coverage is 90.00%.

@@             Coverage Diff             @@
##           develop    #3743      +/-   ##
===========================================
- Coverage    85.79%   85.56%   -0.23%     
===========================================
  Files          302      302              
  Lines       286529   286544      +15     
===========================================
- Hits        245830   245187     -643     
- Misses       40699    41357     +658     

Impacted Files	Coverage Δ
testnet/stacks-node/src/tests/neon_integrations.rs	82.91% <83.33%> (-0.47%)	⬇️
testnet/stacks-node/src/tests/epoch_22.rs	96.17% <100.00%> (+<0.01%)	⬆️
testnet/stacks-node/src/tests/epoch_23.rs	99.63% <100.00%> (+<0.01%)	⬆️

... and 45 files with indirect coverage changes

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[obycode]

Looks fine to me. 👍

[blockstack-devops]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.