release-22.2: upgrades: add missing statement_diagnostics_requests check

[ajwerner]

The migration written for system.statement_diagnostics_requests to support probabilistic collection forgot to add the check constraint. Unfortunately, the roachtest to ensure that the system database after the upgrade matches the bootstrapped schema was itself broken for a while, so we missed it.

It's not quite clear what to do for existing clusters which have been upgraded, but at least we can fix it for future upgrades.

Maybe we'll need to write a migration such that 23.1 adds the check if it does not exist.

Epic: none

Release justification: fixes a bug in a migration

Fixes: #95503

Release note (bug fix): Fixed a bug whereby a system check constraint on statement_diagnostics_requests was not properly added when upgrading from the previous release.

[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?

_{🦉 Hoot! I am a Blathers, a bot for CockroachDB. My owner is dev-inf.}

[cockroach-teamcity]

This change is 

[irfansharif]

Sorry for introducing the bug, this was silly! We have this defensive code that checks for the right bounds before doing the row insert. The only "public" way to insert rows into this table is to use crdb_internal.request_statement_bundle. So unless a user has mucked with the table directly, perhaps we can assume that the contents of the table are sound/abiding the check constraint that we failed to add for upgrades into 22.2.{1-3}. All of which is to say that "Maybe we'll need to write a migration such that 23.1 adds the check if it does not exist" sounds good to me. You've already done all the work with checkConstraintExists -- do you want send the 23.1 patch or should I?

cockroach/pkg/sql/stmtdiagnostics/statement_diagnostics.go

Lines 292 to 296 in 2f81142

	if samplingProbability < 0 || samplingProbability > 1 {
	return 0, errors.Newf(
	"expected sampling probability in range [0.0, 1.0], got %f",
	samplingProbability)
	}

[ajwerner]

do you want send the 23.1 patch or should I?

If you're willing, that'd be great