ci: parse changed files as JSON (#37372)

Avoid interpolating changed file names directly into shell scripts when
building CI matrices.

.github/workflows/check_diffs.yml

@@ -54,11 +54,15 @@ jobs:
       - name: "📂 Get Changed Files"
         id: files
         uses: Ana06/get-changed-files@25f79e676e7ea1868813e21465014798211fad8c # v2.3.0
+        with:
+          format: json
       - name: "🔍 Analyze Changed Files & Generate Build Matrix"
         id: set-matrix
+        env:
+          ALL_CHANGED_FILES: ${{ steps.files.outputs.all }}
         run: |
           python -m pip install packaging requests
-          python .github/scripts/check_diff.py ${{ steps.files.outputs.all }} >> $GITHUB_OUTPUT
+          python .github/scripts/check_diff.py "$ALL_CHANGED_FILES" >> $GITHUB_OUTPUT
     outputs:
       lint: ${{ steps.set-matrix.outputs.lint }}
       test: ${{ steps.set-matrix.outputs.test }}