chore(deps): Bump shivammathur/setup-php from 2.25.4 to 2.28.0

Bumps [shivammathur/setup-php](https://github.com/shivammathur/setup-php) from 2.25.4 to 2.28.0.
- [Release notes](https://github.com/shivammathur/setup-php/releases)
- [Commits](4bd44f22a9...e6f75134d3)

---
updated-dependencies:
- dependency-name: shivammathur/setup-php
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

.github/workflows/openapi.yml

@@ -20,7 +20,7 @@ jobs:
           submodules: true
 
       - name: Set up php
-        uses: shivammathur/setup-php@4bd44f22a98a19e0950cbad5f31095157cc9621b # v2
+        uses: shivammathur/setup-php@e6f75134d35752277f093989e72e140eaa222f35 # v2
         with:
           php-version: '8.1'
           # https://docs.nextcloud.com/server/stable/admin_manual/installation/source_installation.html#prerequisites-for-manual-installation