ci: bump codecov/codecov-action from 3.1.5 to 3.1.6

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 3.1.5 to 3.1.6.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@4fe8c5f...ab904c4)

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

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

Author: dependabot[bot]

.github/workflows/code_coverage.yml

@@ -25,6 +25,6 @@ jobs:
           cargo +nightly tarpaulin --verbose --all-features --workspace --timeout 120 --out xml
 
       - name: Upload to codecov.io
-        uses: codecov/codecov-action@4fe8c5f003fae66aa5ebb77cfd3e7bfbbda0b6b0
+        uses: codecov/codecov-action@ab904c41d6ece82784817410c45d8b8c02684457
         with:
           fail_ci_if_error: true