release-24.1: sql: override StmtTimeout to 0 for sessionless IE

[annrpom]

Backport 2/2 commits from #129489.

/cc @cockroachdb/release

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For queries issued by a sessionless internal executor,
we inherit values from cluster settings. This means
that setting a cluster-wide statement timeout will
impact processes that use a sessionless internal
executor: background jobs, db console, cloud sql
shell, etc. This behavior doesn't make sense in most
cases; so, this patch will override the statement timeout
to 0s (i.e. none).

For the cloud sql shell, this change makes sense as there
is a default payload request timeout applied to these
queries (5s).

Fixes: #126261
Release note (bug fix): Internally issued queries that are not
initiated within a SQL session no longer respect a statement timeout.
This includes: background jobs, queries issued by the db
console that perform introspection, and the cloud sql shell.

---

Release justification: high-prio fix for support customer

[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.
• Backports should not break backwards-compatibility.
• Backports should change as little code as possible.
• Backports should not change on-disk formats or node communication protocols.
• Backports should not add new functionality (except as defined
  here).
• Backports must not add, edit, or otherwise modify cluster versions; or add version gates.
• All backports must be reviewed by the owning areas TL. For more information as to how that review should be conducted, please consult the backport
  policy.

If your backport adds new functionality, please ensure that the following additional criteria are satisfied:

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
• The new functionality is additive-only and only runs for clusters which have specifically “opted in” to it (e.g. by a cluster setting).
• New code is protected by a conditional check that is trivial to verify and ensures that it only runs for opt-in clusters. State changes must be further protected such that nodes running old binaries will not be negatively impacted by the new state (with a mixed version test added).
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.
• Your backport must be accompanied by a post to the appropriate Slack
  channel (#db-backports-point-releases or #db-backports-XX-X-release) for awareness and discussion.

Also, please add a brief release justification to the body of your PR to justify this
backport.

[cockroach-teamcity]

This change is