CNDB-17193 Support Python 3.12 and 3.13 in cqlsh by vendoring pyasyncore

[michaelsembwever]

What is the issue

Provide support for using cqlsh with python 3.12 and 3.13

What does this PR fix and why was it fixed

Backports CASSANDRA-20997.
This also backports CASSANDRA-17832 and CASSANDRA-17417 , resulting in support for python-2.7 being dropped.

[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-2312 rejected by Butler

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8 regressions found
See build details here

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Found 8 new test failures

Test	Explanation	Runs	Upstream
cqlsh_tests.test_cqlsh.TestCqlshSmoke.test_copy_stdout (offheap-bti)	REGRESSION	🔴	0 / 30
o.a.c.distributed.test.AbortedQueryLoggerTest.testLogsReadMetrics	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorCompaction100dTest.testOneToOneCompaction[version=ec enableNVQ=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorKeyRestrictedOnPartitionTest.partitionRestrictedWidePartitionPqCompressedTest[version=ca enableNVQ=false enableFused=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorSiftSmallTest.testCompaction[version=ed enableNVQ=true enableFused=false]	REGRESSION	🔴	0 / 30
o.a.c.index.sai.cql.VectorTypeTest.unknown	NEW	🔴	0 / 30
o.a.c.io.util.PrefetchingRebuffererTest.testNonSequentialAccess (compression)	REGRESSION	🔴	0 / 30
o.a.c.tools.cqlsh.CqlshTest.testKeyspaceRequired (compression)	REGRESSION	🔴	0 / 30

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Found 4 known test failures

[bereng]

Here is an attempt to use this in HCD-1.1 but cqlsh seems to fail with either driver 3.30 o 3.29. My 2cts.