build(deps): update pytest-cov requirement in /.dagger-ci/daggerci

Updates the requirements on [pytest-cov](https://github.com/pytest-dev/pytest-cov) to permit the latest version.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:production
...

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

.dagger-ci/daggerci/requirements.txt

@@ -3,7 +3,7 @@ dagger-io~=0.13
 prettytable~=3.11
 pytest~=8.3
 pytest-benchmark~=5.0
-pytest-cov~=5.0
+pytest-cov~=6.0
 pytest-flake8~=1.2
 pytest-pylint~=0.21
 pytest-timeout~=2.3