Improve unit test path filtering rules (#2052)

* Improve path-filtering rules on unit test action

See docs about how jobs that are skipped still report "success", which
is necessary for jobs that are required to succeed based on branch
protection rules.

https://docs.github.com/en/actions/using-jobs/using-conditions-to-control-job-execution

* Code must be checked out for paths-filter to run

* Only run on default pull request events

Defaults are that it will run when a PR is opened, reopened, or
synchronized (new commits pushed).

.github/workflows/nodejs.yml

@@ -2,31 +2,36 @@
 name: Node CI
 
 on:
-  push:
-    paths-ignore:
-      - '**/*.md'
-      - '**/*.asciidoc'
-      - '**/*.txt'
-      - 'docs/**'
-      - '.ci/**'
-      - '.buildkite/**'
-      - 'scripts/**'
-      - 'catalog-info.yaml'
-  pull_request:
-    paths-ignore:
-      - '**/*.md'
-      - '**/*.asciidoc'
-      - '**/*.txt'
-      - 'docs/**'
-      - '.ci/**'
-      - '.buildkite/**'
-      - 'scripts/**'
-      - 'catalog-info.yaml'
+  pull_request: {}
 
 jobs:
+  paths-filter:
+    name: Detect files changed
+    runs-on: ubuntu-latest
+    outputs:
+      skip: '${{ steps.changes.outputs.skip }}'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter/@v2.11.1
+        id: changes
+        with:
+          filters: |
+            skip:
+              - '**/*.md'
+              - '**/*.asciidoc'
+              - '**/*.txt'
+              - 'docs/**'
+              - '.ci/**'
+              - '.buildkite/**'
+              - 'scripts/**'
+              - 'catalog-info.yaml'
+
   test:
     name: Test
     runs-on: ${{ matrix.os }}
+    needs: paths-filter
+    # only run if files not in `skip` filter were changed
+    if: needs.paths-filter.outputs.skip != 'true'
 
     strategy:
       fail-fast: false
@@ -35,7 +40,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macOS-latest]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Use Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v3