Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/2068

Reference: https://ansible-lint.readthedocs.io/en/latest/default_rules/#git-latest

Our variable naming is not necessarily consistent across roles.
I've tried to follow the naming conventions of each individual role.
All new variables are suffixed with `_version`, but the prefix may be
somewhat different.

* matrix-backup-borg: added option for unencrypted repo access

* matrix-backup-borg: fixed requiring password for unencrypted repos; changed variable name

* matrix-backup-borg: add unknown_unencrypted_repo_access_is_ok to config.yaml.j2

* matrix-backup-borg: cleanup comments

* matrix-backup-borg: add documentation regarding unencrypted repos

* matrix-backup-borg: add readability and ease of use to code

* matrix-backup-borg: fix wording in defaults/main.yml comment

* matrix-backup-borg: add quotes to docs

* Indicate the variable to use

Co-authored-by: Slavi Pantaleev <slavi@devture.com>

* add borg backup

* lint fix

* add exlclude patterns

* missed in the #1726 fix for honoroit

* feedback

* Fix indentation

* feedback

* feedback

* feedback

Co-authored-by: Slavi Pantaleev <slavi@devture.com>