previously disable the cache update was only possible on ubuntu
using the generic name wireguard_update_cache it can be enabled for all
operating systems
* move wireguard_private_key up in variable order in defaults/main.yml
* add opensuse 15.3 to Galaxy metadata
* remove trailing space
* remove blank line
* fix indentation in setup-debian.yml
* rename test-wg-opensuse-leap to test-wg-opensuse-leap-15-2 in molecule.yml
* add OpenSUSE 15.3 to Molecule test
* remove OpenSUSE Leap 15.2 support (EOL)
* remove Fedora 33 support (EOL)
* remove Fedora 33 + openSUSE Leap 15.2 variables from Molecule test
* add Fedora 35 support
* remove CentOS 8 support (EOL) - use AlmaLinux or Rocky Linux instead
* remove tasks/setup-centos-8.yml (CentOS 8 reached EOL)
* fix formatting issues and typos in README + CHANGELOG
* update CHANGELOG
* truthy value should false in tasks/setup-debian-pve-guest-variant.yml
* name task in tasks/main.yml
* name tasks in tasks/setup-debian.yml
* refactor Molecule setup
* remove Proxmox from Molecule test
* update CHANGELOG
* update CHANGELOG
* re-order IP address in Molecule test
* use different wireguard_port values for a few hosts in Molecule test for better testing