Revert "Update workers to self hosted" (#638)

.github/workflows/verify-generated-headers.yml

@@ -18,7 +18,7 @@ jobs:
             generator: bash ./hook/generate_sfcodes.sh
           - target: hook/tts.h
             generator: ./hook/generate_tts.sh
-    runs-on: [self-hosted, generic]
+    runs-on: ubuntu-latest
     name: ${{ matrix.target }}
     steps:
       - name: Checkout repository