Bump codecov/codecov-action from 6 to 7

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 6 to 7.
- [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/v6...v7)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/tests.yml

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 87bd0d1..81f4d32 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -69,7 +69,7 @@
         if: startsWith(matrix.os, 'ubuntu')
       - run: pytest codespell_lib
         if: startsWith(matrix.os, 'windows')
-      - uses: codecov/codecov-action@v6
+      - uses: codecov/codecov-action@v7
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
       # tomli should not be required for the next two steps (and make sure it's not)