Bump codecov/codecov-action from 5 to 6 (#1063)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 5 to 6.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v5...v6)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-version: '6'
  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/ci.yml

@@ -166,7 +166,7 @@ jobs:
 
       - name: Code Coverage Report
         if: success() && matrix.php-version == '8.1' && matrix.db-type == 'mysql'
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
 
   testsuite-windows:
     runs-on: windows-2022
@@ -240,7 +240,7 @@ jobs:
           vendor/bin/phpunit --coverage-clover=coverage.xml
 
     - name: Submit code coverage
-      uses: codecov/codecov-action@v5
+      uses: codecov/codecov-action@v6
 
   cs-stan:
     uses: cakephp/.github/.github/workflows/cs-stan.yml@5.x