CNDB-16145: Split VectorSiftSmallTest to prevent JUnit timeouts

[adelapena]

What is the issue

VectorSiftSmallTest frequently hits JUnit timeouts, likely due to the test being too long.

What does this PR fix and why was it fixed

Splits VectorSiftSmallTest into multiple smaller tests.

Please note that this doesn't aim to fix https://github.com/riptano/cndb/issues/16316, which is a separate problem.

[github-actions]

Checklist before you submit for review

• This PR adheres to the Definition of Done
• 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
• All new files should contain the DataStax copyright header instead of the Apache License one

[cassci-bot]

❌ Build ds-cassandra-pr-gate/PR-2263 rejected by Butler

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3 regressions found
See build details here

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Found 3 new test failures

Test	Explanation	Runs	Upstream
o.a.c.distributed.test.AbortedQueryLoggerTest.testLogsReadMetrics	REGRESSION	🔴	0 / 21
o.a.c.index.sai.cql.VectorCompaction100dTest.testOneToManyCompaction[ec false]	REGRESSION	🔴	0 / 21
o.a.c.index.sai.cql.VectorSiftSmallCompactionTest.testCompaction[ca false false]	NEW	🔴	0 / 21

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Found 3 known test failures

[michaeljmarshall]

We certain can keep this change, but in my recent testing of some CI pipeline improvements https://github.com/riptano/jenkins-pipeline-lib/pull/250, I discovered that this test goes from ~25 minutes to ~8 minutes, so it will be much more likely to succeed without needing to split it out.

I haven't reviewed it yet, but I think we should wait until https://github.com/riptano/jenkins-pipeline-lib/pull/250 lands (hopefully tomorrow) before merging this.