chore(deps): bump codecov/codecov-action from 5 to 6

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>

Author: dependabot[bot]

.github/workflows/commit.yml

@@ -103,7 +103,7 @@ jobs:
 
       - name: Upload coverage
         if: github.repository_owner == 'modflowpy' && (github.event_name == 'push' || github.event_name == 'pull_request')
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           files: autotest/coverage.xml
 
@@ -194,6 +194,6 @@ jobs:
 
       - name: Upload coverage
         if: github.repository_owner == 'modflowpy' && (github.event_name == 'push' || github.event_name == 'pull_request')
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           files: flopy/autotest/coverage.xml

.github/workflows/mf6.yml

@@ -86,7 +86,7 @@ jobs:
     - name: Upload coverage to Codecov
       if:
         github.repository_owner == 'modflowpy' && (github.event_name == 'push' || github.event_name == 'pull_request')
-      uses: codecov/codecov-action@v5
+      uses: codecov/codecov-action@v6
       with:
         files: ./modflow6/autotest/coverage.xml