CNDB-17376 Remove branch name from Jenkinsfile

[djatnieks]

What is the issue

CNDB-17376

What does this PR fix and why was it fixed

Remove branch name from Jenkinsfile

[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

[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

[cassci-bot]

❌ Build ds-cassandra-pr-gate/PR-2305 rejected by Butler

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6 regressions found
See build details here

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Found 6 new test failures

Test	Explanation	Runs	Upstream
replica_side_filtering_test.TestAllowFiltering.test_update_on_static_column_with_not_empty_partition (offheap-bti)	REGRESSION	🔴	0 / 30
o.a.c.distributed.test.AbortedQueryLoggerTest.testLogsReadMetrics	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorCompaction100dTest.testOneToManyCompaction[version=ec enableNVQ=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorKeyRestrictedOnPartitionTest.partitionRestrictedTest[version=ed enableNVQ=true enableFused=false] (compression)	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorKeyRestrictedOnPartitionTest.partitionRestrictedWidePartitionBqCompressedTest[version=eb enableNVQ=false enableFused=false] (compression)	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorSiftSmallTest.testMultiSegmentBuild[version=ed enableNVQ=true enableFused=false]	REGRESSION	🔴	0 / 30

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Found 5 known test failures