release-23.2: sqlstats: add retries to stats test on locked table

[blathers-crl]

Backport 1/1 commits from #119977 on behalf of @dhartunian.

/cc @cockroachdb/release

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Previously, the TestSQLStatsReadLimitSizeOnLockedTable test would fail very occasionally due to a rare scenario. When stats are written, they contain a column that's a hashed shard index. It's expected that statements are uniformly distributed across this shard, but that's not guaranteed. Later in the test we check a random shard to make sure its stats count exceeds a minimum of 1 (because we place a total lower bound of 8 in the cluster setting, which is then divided by 8 to derive the per-shard limit). This case will occasionally fail if the random shard that's picked happens to only contain a single statement within.

This change modifies the loop at the end of the test to expect a false value and make sure to get at least a single true result after 3 iterations, instead of requiring 3 true results every single time. The requirement that the queries run despite contention will still stand since we'll return an error in that case.

Resolves: #119067
Epic: None

Release note: None

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Release justification:

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

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[cockroach-teamcity]

This change is