ci: Add Action to check for tabs in JSON files

.github/workflows/no-tabs.yml

@@ -0,0 +1,19 @@
+name: Check for tabs in JSON files
+
+on: [push, pull_request]
+
+jobs:
+  check-for-tabs-in-json:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check JSON files for tabs
+        run: |
+          set -e
+
+          for file in $(find . -type f -name '*.json'); do
+            if grep --perl-regexp --quiet '\t' "$file"; then
+              echo "Error: JSON file $file contains tabs."
+              exit 1
+            fi
+          done