release-24.3: sql: allow CLOSE CURSOR in read-only txns

[blathers-crl]

Backport 1/1 commits from #137744 on behalf of @yuzefovich.

/cc @cockroachdb/release

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This is allowed in PG, so we now will allow this too. The fix is similar to what we did for DECLARE and FETCH in 50a7999.

Fixes: #137606.

Release note (bug fix): CLOSE CURSOR statements are now allowed in read-only transactions, similat to Postgres. The bug has been present since at least 23.1 version.

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Release justification: bug fix.

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Backports should only be created for serious
  issues or test-only changes.
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[cockroach-teamcity]

This change is