chore(ci): integration test suite enhancements

[pront]

Summary

We can detect if we can skip all jobs before spawning 33 jobs each time.

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

• Run when source code was changed: https://github.com/vectordotdev/vector/actions/runs/12835355683?pr=22237
• Run without any source code changes: https://github.com/vectordotdev/vector/actions/runs/12835784383

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Please read our Vector contributor resources.
  • make check-all is a good command to run locally. This check is
    defined here. Some of these
    checks might not be relevant to your PR. For Rust changes, at the very least you should run:
    • cargo fmt --all
    • cargo clippy --workspace --all-targets -- -D warnings
    • cargo nextest run --workspace (alternatively, you can run cargo test --all)
• If this PR introduces changes Vector dependencies (modifies Cargo.lock), please
  run dd-rust-license-tool write to regenerate the license inventory and commit the changes (if any). More details here.

References

Ref: #22205

[datadog-vectordotdev]

Datadog Report

Branch report: pront/tweak-it-suite
Commit report: aa20581
Test service: vector

✅ 0 Failed, 7 Passed, 0 Skipped, 25.5s Total Time