build(deps): bump peter-evans/repository-dispatch from 3 to 4

Bumps [peter-evans/repository-dispatch](https://github.com/peter-evans/repository-dispatch) from 3 to 4.
- [Release notes](https://github.com/peter-evans/repository-dispatch/releases)
- [Commits](peter-evans/repository-dispatch@v3...v4)

---
updated-dependencies:
- dependency-name: peter-evans/repository-dispatch
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/docs.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Trigger docs build
-        uses: peter-evans/repository-dispatch@v3
+        uses: peter-evans/repository-dispatch@v4
         with:
           repository: psycopg/psycopg-website
           event-type: psycopg2-commit