Bump pylint from 2.15.5 to 2.15.6 in /requirements.d

Bumps [pylint](https://github.com/PyCQA/pylint) from 2.15.5 to 2.15.6.
- [Release notes](https://github.com/PyCQA/pylint/releases)
- [Commits](pylint-dev/pylint@v2.15.5...v2.15.6)

---
updated-dependencies:
- dependency-name: pylint
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.d/lint.txt

@@ -1,6 +1,6 @@
 # Requirements for base linting tools
 
 yamllint==1.28.0
-pylint==2.15.5
+pylint==2.15.6
 shellcheck-py==0.8.0.3
 ansible-lint[community]==5.4.0