CI: bring GitHub Actions fuzzing job in line with macOS jobs

Update YAML formatting, job naming and triggers.

.github/workflows/fuzz.yml

@@ -1,7 +1,9 @@
-name: CIFuzz
-on: [pull_request]
+name: CI
+
+on: [push, pull_request]
+
 jobs:
-  Fuzzing:
+  fuzzing:
     runs-on: ubuntu-latest
     steps:
     - name: Build Fuzzers
@@ -9,12 +11,14 @@ jobs:
       with:
         oss-fuzz-project-name: 'curl'
         dry-run: false
+
     - name: Run Fuzzers
       uses: google/oss-fuzz/infra/cifuzz/actions/run_fuzzers@master
       with:
         oss-fuzz-project-name: 'curl'
         fuzz-seconds: 600
         dry-run: false
+
     - name: Upload Crash
       uses: actions/upload-artifact@v1
       if: failure()