MNT: (deps): Bump codecov/codecov-action from 3 to 4

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 3 to 4.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v3...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/tests-conda.yml

@@ -76,6 +76,6 @@ jobs:
 
     - name: Upload coverage
       if: ${{ always() }}
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         name: conda-${{ matrix.python-version }}-${{ runner.os }}

.github/workflows/tests-pypi.yml

@@ -84,6 +84,6 @@ jobs:
 
     - name: Upload coverage
       if: ${{ always() }}
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
       with:
         name: pypi-${{ matrix.python-version }}-${{ matrix.dep-versions }}-${{ matrix.no-extras }}-${{ runner.os }}