CNDB-11574 main-5.0: Fix VectorCompressionTest.testBert

[adelapena]

For now, improve assertions to be a bit more informative and increase the timeout of the waiting for the index build.

Checklist before you submit for review

• Make sure there is a PR in the CNDB project updating the Converged Cassandra version
• Use NoSpamLogger for log lines that may appear frequently in the logs
• Verify test results on Butler
• Test coverage for new/modified code is > 80%
• Proper code formatting
• Proper title for each commit staring with the project-issue number, like CNDB-1234
• Each commit has a meaningful description
• Each commit is not very long and contains related changes
• Renames, moves and reformatting are in distinct commits

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[cassci-bot]

❌ Build ds-cassandra-pr-gate/PR-1401 rejected by Butler

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7 new test failure(s) in 1 builds
See build details here

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Found 7 new test failures

Test	Explanation	Branch history	Upstream history
t.TestCqlshUnicode.test_unicode_desc	failing	🔴
t.TestCqlshUnicode.test_unicode_identifier	failing	🔴
...adCommitLogAndSSTablesWithDroppedColumnTestCC40	failing	🔴
...adCommitLogAndSSTablesWithDroppedColumnTestCC50	failing	🔴
...oadCommitLogAndSSTablesWithDroppedColumnTestDSE	failing	🔴
...thRestartTest.testReadingValuesOfDroppedColumns	failing	🔴
...rrorsTest.testNoSuchRepairSessionAnticompaction	failing	🔴

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No known test failures found

[ekaterinadimitrova2]

I prefer the new logging, which also shows us the exact number of SSTables, and not just a single 1.
I was wondering if you tried the Jenkins multiplexer when you mentioned this was not reproducible. Does it work? I haven't tried the multiplexer myself. If you haven't tried that one, maybe we should do it?

[ekaterinadimitrova2]

This was not moved to ready for review but the patch is identical to the main patch, we have the repeated runs posted on the actual GH issues showing the flakiness is clean so I approve it to be committed after PR gate approves too. Thanks!