collection: Update min Ansible version and update workflows

[marcelmamula]

Changes

• Change of minimum Ansible version to 2.18 which is currently being applied across whole project.

  • NOTE: This change caused incompatibility with ansible-test workflow for EOL version and as result those tests were commented out.

• Update README.md to reflect version changes.

• Update workflows:

  • Updated schedule to avoid conflict with other collections in project.
    • sap_libs workflows run daily.
    • All other collections have dedicated weekday and run weekly (ansible-lint runs 1 hour after ansible-test).
  • Add parallel limit to reduce API issues.
  • Updated Ansible Lint to v26
  • Updated path list to disable sanity tests when only documentation is updated.

[rhmk]

LGTM