replace changed-files action with git-fu

Author: lorennorman

.github/workflows/validate.yml

@@ -38,7 +38,13 @@ jobs:
       - name: List All Changed Files
         if:  ${{ !inputs.all_files }}
         id: list-changed-files
-        uses: tj-actions/changed-files@v37
+        run: |
+          # also fetch main to diff against
+          git fetch --depth=1 origin main
+          # list Added, Copied, Modified, and Renamed files
+          ACMR_FILES=`git diff origin/main --name-only --diff-filter=ACMR | xargs`
+          # GitHub Actions output ritual
+          echo "all_changed_files=$ACMR_FILES" >> "$GITHUB_OUTPUT"
       - name: List All Component Files
         if:  ${{ inputs.all_files }}
         id: list-all-files