CNDB-17291: Fix SlowSAIQueryLoggerTest

[adelapena]

What is the issue

CNDB-17275 broke SlowSAIQueryLoggerTest by disabling the use of term stats by the query optimizer by default. While disabled in production, the usage of term stats is enabled by default for utests extending SAITester. However, the SlowSAIQueryLoggerTest dtest doesn't extend SAITester, so it broke after that change. That first failure can be seen in the CI results for CNDB-17275: #2290 (comment)

What does this PR fix and why was it fixed

Enable SAI_QUERY_OPTIMIZATION_USE_TERM_STATISTICS in SlowSAIQueryLoggerTest to preserve the original behaviour.

[github-actions]

Checklist before you submit for review

• This PR adheres to the Definition of Done
• Make sure there is a PR and ticket 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 IBM copyright header instead of the Apache License one (no DataStax copyright any longer)

[sonarqubecloud]

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 SonarQube Cloud

[plpesvc-ds]

❌ Build ds-cassandra-pr-gate/PR-2427 rejected by Butler

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4 regressions found
See build details here

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Found 4 new test failures

Test	Explanation	Runs	Upstream
o.a.c.index.sai.cql.VectorCompaction100dTest.testPQRefine[version=ec enableNVQ=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorKeyRestrictedOnPartitionTest.partitionRestrictedWidePartitionBqCompressedTest[version=ca enableNVQ=false enableFused=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorSiftSmallTest.testSiftSmall[version=fa enableNVQ=false enableFused=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorTypeTest.lwtTest[version=ca enableNVQ=false enableFused=false]	REGRESSION	🔴	0 / 30

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Found 3 known test failures