ci: bump peter-evans/create-pull-request from 6 to 8 (#3)

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 6 to 8.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@v6...v8)

---
updated-dependencies:
- dependency-name: peter-evans/create-pull-request
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/spec-drift.yml

@@ -22,7 +22,7 @@ jobs:
         continue-on-error: true
         run: pytest tests/live -v
       - name: Open PR if models changed
-        uses: peter-evans/create-pull-request@v6
+        uses: peter-evans/create-pull-request@v8
         with:
           branch: bot/spec-drift
           commit-message: "chore: regenerate models from upstream spec"