.github: bump peter-evans/create-pull-request from 5.0.1 to 6.0.4

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 5.0.1 to 6.0.4.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](284f54f989...9153d834b6)

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

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/update-flake.yml

@@ -35,7 +35,7 @@ jobs:
           private_key: ${{ secrets.LICENSING_APP_PRIVATE_KEY }}
 
       - name: Send pull request
-        uses: peter-evans/create-pull-request@284f54f989303d2699d373481a0cfa13ad5a6666 #v5.0.1
+        uses: peter-evans/create-pull-request@9153d834b60caba6d51c9b9510b087acf9f33f83 #v6.0.4
         with:
           token: ${{ steps.generate-token.outputs.token }}
           author: Flakes Updater <noreply+flakes-updater@tailscale.com>

.github/workflows/update-webclient-prebuilt.yml

@@ -34,7 +34,7 @@ jobs:
 
       - name: Send pull request
         id: pull-request
-        uses: peter-evans/create-pull-request@284f54f989303d2699d373481a0cfa13ad5a6666 #v5.0.1
+        uses: peter-evans/create-pull-request@9153d834b60caba6d51c9b9510b087acf9f33f83 #v6.0.4
         with:
           token: ${{ steps.generate-token.outputs.token }}
           author: OSS Updater <noreply+oss-updater@tailscale.com>