[deps] Update ansible-core requirement from ~=2.18.0 to ~=2.20.2

Updates the requirements on [ansible-core](https://github.com/ansible/ansible) to permit the latest version.
- [Release notes](https://github.com/ansible/ansible/releases)
- [Commits](ansible/ansible@v2.18.0...v2.20.2)

---
updated-dependencies:
- dependency-name: ansible-core
  dependency-version: 2.20.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements-test.txt

@@ -1,6 +1,6 @@
 molecule
 molecule-plugins[docker]
-ansible-core~=2.18.0
+ansible-core~=2.20.2
 yamllint
 ansible-lint
 docker