Add postgres version matrix to phpunit tests

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 5.4.2 to 5.4.3.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/codecov/codecov-action/compare/v5.4.2...v5.4.3)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-version: 5.4.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/phpunit.yml

@@ -6,10 +6,13 @@ jobs:
   phpunit:
     runs-on: ubuntu-latest
     timeout-minutes: 10
+    strategy:
+      matrix:
+        postgres_version: [ 15, 16, 17 ]
 
     services:
       pgsql_test:
-        image: postgres:15
+        image: postgres:${{ matrix.postgres_version }}
         env:
           PGPASSWORD: 'root'
           POSTGRES_DB: 'laravel'
@@ -65,7 +68,7 @@ jobs:
         run: php artisan test --stop-on-failure --coverage-text --coverage-clover=coverage.xml
 
       - name: "Upload coverage reports to Codecov"
-        uses: codecov/codecov-action@v5.4.2
+        uses: codecov/codecov-action@v5.4.3
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           slug: solidtime-io/solidtime