* feat: latest Alpine 3.23.0
* feat: latest Rsync 3.4.1-r1
* feat: integrate [rsync-docker](https://github.com/JoshPiper/rsync-docker/) 3rd party into this action as 1st party code (no more dependency, better audit, single source of truth)
- backported:
- agent-start
- agent-stop
- agent-askpass
- agent-add
- hosts-add
- hosts-clear
- new added:
- ssh-init
- hosts-init
- improved:
- stricter permissions on .ssh/ folder (700) and known_hosts (600)
- use set -eu in all scipts
* feat: new ``strict_host_keys`` option to enable support for strict host key verification. Default: false (to keep backward compatibility)
* feat: new ``debug`` option to see the commands executed (-x) by this action
* feat: this action is now scanned for vulnerabilities by Snyk
* feat; this action is now scanned by CodeQL for Q/A
* feat: this action now performs CI tasks such as Validation, Linting and Unit Tests
* fix: various shell syntax for robustness
* fix: use printf and redirect output to non-stdout instead of echo in sensitive code locations
* refactor: use $HOME instead of tilde ~ for robustness
* feat: cross-platform support
* chore: Deprecate 7.0.2
* chore: EOL 7.0.0 & 7.0.1
* update base image drinternet/rsync:v1.3.0
* Base Image updates: alpine 3.14.1 latest
* use v5.1 in examples
* support for v5.x
* mention Alpine version