release-23.2: c2c: prevent NPE in SHOW TENANT WITH REPLICATION STATUS

[blathers-crl]

Backport 1/1 commits from #120434 on behalf of @msbutler.

/cc @cockroachdb/release

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If the user ran SHOW TENANT ... WITH REPLICATION STATUS before the stream ingestion job pts was set, a null pointer exception would occur and crash the node. This patch fixes this bug.

Epic: None

Release note: none

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Release justification: low risk 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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  here).
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Also, please add a brief release justification to the body of your PR to justify this
backport.

[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 

[msbutler]

closing in favor of #120779