refactor: Replace 'on: pull_request: paths' by 'changed-files' action (#5728)

This PR moves the list of files from the `paths:` section in the `on: pull_request` into a separate job.

.github/workflows/on-trigger.yml

@@ -13,31 +13,33 @@ on:
       - release
       - master
     paths:
+      # These paths are unique to `on-trigger.yml`.
+      - ".github/workflows/check-missing-commits.yml"
+      - ".github/workflows/on-trigger.yml"
+      - ".github/workflows/publish-docs.yml"
+
+      # Keep the paths below in sync with those in `on-pr.yml`.
       - ".github/actions/build-deps/**"
       - ".github/actions/build-test/**"
       - ".github/scripts/strategy-matrix/**"
       - ".github/workflows/build-test.yml"
-      - ".github/workflows/check-missing-commits.yml"
-      - ".github/workflows/on-trigger.yml"
-      - ".github/workflows/publish-docs.yml"
-      # Keep the list of paths below in sync with those in `on-pr.yml`.
+      - ".codecov.yml"
       - "cmake/**"
       - "conan/**"
       - "external/**"
       - "include/**"
       - "src/**"
       - "tests/**"
-      - ".clang-format"
-      - ".codecov.yml"
-      - ".pre-commit-config.yaml"
       - "CMakeLists.txt"
       - "conanfile.py"
+
   # Run at 06:32 UTC on every day of the week from Monday through Friday. This
   # will force all dependencies to be rebuilt, which is useful to verify that
   # all dependencies can be built successfully. Only the dependencies that
   # are actually missing from the remote will be uploaded.
   schedule:
     - cron: "32 6 * * 1-5"
+
   # Run when manually triggered via the GitHub UI or API. If `force_upload` is
   # true, then the dependencies that were missing (`force_rebuild` is false) or
   # rebuilt (`force_rebuild` is true) will be uploaded, overwriting existing