ci: add fuzzing of pull requests for 20 minutes

To increase our testing coverage before merging. This uses already build
corpus and coverage info to test the modified code, if possible.

See: https://google.github.io/oss-fuzz/getting-started/continuous-integration

.github/workflows/fuzz.yml

@@ -0,0 +1,44 @@
+name: Pull Request Fuzzing
+on:
+  pull_request:
+    branches: [master]
+    paths-ignore:
+        - 'DOCS/**'
+        - 'TOOLS/lua/**'
+        - '.editorconfig'
+        - '.gitignore'
+        - 'Copyright'
+        - 'README.md'
+        - 'RELEASE_NOTES'
+permissions: {}
+jobs:
+  Fuzzing:
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+    steps:
+    - name: Build Fuzzers
+      id: build
+      uses: google/oss-fuzz/infra/cifuzz/actions/build_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'mpv'
+        language: c
+    - name: Run Fuzzers
+      uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
+      with:
+        oss-fuzz-project-name: 'mpv'
+        language: c
+        fuzz-seconds: 1200
+        output-sarif: true
+    - name: Upload Crash
+      uses: actions/upload-artifact@v4
+      if: failure() && steps.build.outcome == 'success'
+      with:
+        name: artifacts
+        path: ./out/artifacts
+    - name: Upload Sarif
+      if: always() && steps.build.outcome == 'success'
+      uses: github/codeql-action/upload-sarif@v3
+      with:
+        sarif_file: cifuzz-sarif/results.sarif
+        checkout_path: cifuzz-sarif