[ansible] JFrog Platform 10.20.0 release

[amithins]

PR Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [x] Title of the PR starts with installer/product name (e.g. [ansible/artifactory])
• [x] CHANGELOG.md updated
• [x] Variables and other changes are documented in the README.md

What this PR does / why we need it:

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer: