Add conditional CI Checks

[phenixblue]

What would you like to be added:

Need to add some conditional logic to certain CI checks to increase efficiency for some PR's.

Why is this needed:

Not all checks need to run on a given PR unless certain files change. Github Actions has filtering capabilities, but it breaks things if you enable that with a required check (https://github.community/t5/GitHub-Actions/Feature-request-conditional-required-checks/m-p/36938#M2735
) and then the check doesn’t trigger in a PR. Until there’s a solution from Github we may need to add the conditional logic into the CI checks themselves.

Use something like this in a helper function that lives somewhere in ./hack. This should be generic to work for any number of directly/file paths and for any CI check.

$ git --no-pager diff --name-only --ignore-blank-lines HEAD $REF -- app

Probably not an exhaustive list, but good to start collecting the specific paths we want to trigger on for each set of checks:

Python Checks

    - /app
    - /.github/workflows

e2e Checks

    - /app
    - /deploy/manifests
    - /policies
    - /hack
    - /.github/workflows

Manifests Checks

    - /deploy/manifests
    - /hack
    - /.github/workflows

[phenixblue]

This may be of use: https://github.com/dorny/paths-filter