delegate: SHOW GRANTS ON TYPE works across DBs

[rafiss]

fixes #67512

Release note (bug fix): Previously, a SHOW GRANTS ON TYPE db.public.typ
command would not correctly show the grants if the current database was
not db. This is fixed now.

[cockroach-teamcity]

This change is 

[rafiss]

tftr!

bors r=RichardJCai

[craig]

Build succeeded:

• GitHub CI (Cockroach)

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 5506ea0 to blathers/backport-release-21.1-68137: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 21.1.x failed. See errors above.

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