release-26.1: sql: clean up dependency graph a bit

[yuzefovich]

Backport 3/3 commits from #160206 on behalf of @yuzefovich.

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This PR contains a few commits that break a few dependencies to allow more parallelism during builds.

Informs: #79357.
Epic: None
Release note: None

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Release justification: no risk build speed up.

[blathers-crl]

Thanks for opening a backport.

Before merging, please confirm that the change does not break backwards compatibility and otherwise complies with the backport policy. Include a brief release justification in the PR description explaining why the backport is appropriate. All backports must be reviewed by the TL for the owning area. While the stricter LTS policy does not yet apply, please exercise judgment and consider gating non-critical changes behind a disabled-by-default feature flag when appropriate.

[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 

[michae2]

@michae2 partially reviewed 16 files and all commit messages, and made 1 comment.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @rafiss).