chore: Upgrade peter-evans/create-pull-request action to v8 (#1056)

Author: renovate[bot]

.github/workflows/benchmark.yaml

@@ -31,7 +31,7 @@ jobs:
           script: |
             core.setOutput('results', require('./docs/data.json').benchmark.results);
       - id: create-pr
-        uses: peter-evans/create-pull-request@v7
+        uses: peter-evans/create-pull-request@v8
         with:
           add-paths: docs/data.json
           base: main