CI: Increases fuzzing time

We have a lot of fuzzers now, let's give them a bit of time

.github/workflows/tests.yml

@@ -319,7 +319,7 @@ jobs:
       - uses: google/clusterfuzzlite/actions/run_fuzzers@v1
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          fuzz-seconds: 600
+          fuzz-seconds: 900
           mode: code-change
           sanitizer: address
           minimize-crashes: true
@@ -341,7 +341,7 @@ jobs:
       - uses: google/clusterfuzzlite/actions/run_fuzzers@v1
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          fuzz-seconds: 3600
+          fuzz-seconds: 7200
           mode: batch
           sanitizer: address
           minimize-crashes: true