Fix validation of Agent deps when using single check

[florimondmanca]

What does this PR do?

Fix behavior of ddev validate dep <check>

Motivation

Found during QA for #8297

Currently $ ddev validate dep nginx fails with a large list of errors:

$ ddev validate dep nginx
Stale dependency needs to be removed by syncing: adodbapi
Stale dependency needs to be removed by syncing: aerospike
Stale dependency needs to be removed by syncing: aws-requests-auth
[...]
Stale dependency needs to be removed by syncing: uptime
Stale dependency needs to be removed by syncing: vertica-python
Stale dependency needs to be removed by syncing: win-inet-pton

This is because when passing a <check>, we currently still validate check_dependencies (which only contains the deps for <check>, rather than the set of all deps for all checks) against agent_dependencies (which contains all dependencies shipped in the Agent).

Instead, I think we should just skip this verification when passing a <check>. If the dependencies for <check> does contain an out-of-sync dependency compared to Agent deps, then we'll notice during the "all checks" run of this job anyway.

With this PR, the validation passes.

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[mgarabed]

👍 Good update - minor formatting nit.

[florimondmanca]

@mgarabed Sure. 👍