fix: add debugging step for types in GH Actions

.github/workflows/run-typescript.yml

@@ -28,5 +28,9 @@ jobs:
         run: |
           npm ci
           npm run build
+      - name: Check for gatsby-types.d.ts
+        run: |
+          ls -l src/gatsby-types.d.ts
+          cat src/gatsby-types.d.ts | head -n 20
       - name: Run TypeScript check
         run: npm run check