ci: run snapshot job when snapshot package.json is modified

Prior of switching to the self hosted Renovate bot, we ran `e2e-cli-ng-snapshots` job on the `main` branch and Renovate PRs that updated the Angular dependencies. Since the switch however we only run this on the `main` branch because the previous branch filter `renovate/angular` doesn't match.

Unfortunately, we can no longer rely on the branch filter as for forked repos circle passes the branch names in the form of `pull/<number>`.

Thus, we use orbs path-filtering together with circle ci dynamic configuration feature.

See: https://circleci.com/developer/orbs/orb/circleci/path-filtering

Author: alan-agius4