release-22.2: sqlstats: increase default value for deleted rows

[blathers-crl]

Backport 1/1 commits from #97642 on behalf of @maryliag.

/cc @cockroachdb/release

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During the sql stats compaction job, we limit the amount of rows being deleted per transaction. We used a default value of 1024, but we have been increasinly seeing customer needing to increase this value to allow the job to keep up with the large amount of data being flushed.
We have been recommening a value for 20k, so being more conservative with the default (plus the changes on #97123 that won't let tables get in a state with so many rows), this commit changes the value to 10k.

Fixes #97528

Release note (sql change): Increase the default value of sql.stats.cleanup.rows_to_delete_per_txn to 10k, to increase efficiency of the cleanup job for sql statistics.

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Release justification: performance improvement

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Patches should only be created for serious issues or test-only changes.
• Patches should not break backwards-compatibility.
• Patches should change as little code as possible.
• Patches should not change on-disk formats or node communication protocols.
• Patches should not add new functionality.
• Patches must not add, edit, or otherwise modify cluster versions; or add version gates.

If some of the basic criteria cannot be satisfied, ensure that the exceptional criteria are satisfied within.

• 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.
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.

Add a brief release justification to the body of your PR to justify this backport.

Some other things to consider:

• What did we do to ensure that a user that doesn’t know & care about this backport, has no idea that it happened?
• Will this work in a cluster of mixed patch versions? Did we test that?
• If a user upgrades a patch version, uses this feature, and then downgrades, what happens?

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

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[cockroach-teamcity]

This change is