Add support for AlmaLinux 8/9 and Rocky Linux 8

[arvindshmicrosoft]

• Add support for AlmaLinux and Rocky Linux in the Ansible playbooks.
• Switch the default Azure VM image to AlmaLinux 9.
• Add an Azure-specific cloud-init file for AlmaLinux 9 to install rsync at first boot, as the image does not seem to install it.
• Add an Ansible task to stop and disable firewalld for AlmaLinux 9, to allow RPC communication within the cluster.
• Use Python to install Ansible on the proxy for non-CentOS OS to ensure a current version of Ansible is used. This avoids problems when the Ansible package in the EL repo is outdated or requires a newer Python than is supported by the given OS.
• While using Rocky Linux 9 is not blocked, there are some external issues with the Azure Linux agent and this OS version.
• These changes have been tested on Azure with various OS images used for the cluster nodes and the "proxy". Currently "known good" OS versions for Azure include Fedora 39, CentOS 7.9, AlmaLinux 8/9, Rocky Linux 8.
• Update references to CentOS 7 in the context of EC2 as the default image for EC2 had already been changed to a Fedora 35 AMI.

[arvindshmicrosoft]

Thanks @ctubbsii the intention here was to get this project to a known good state, nothing more. I don't have any plans to add anything else to Muchos. Thanks for your time reviewing the PRs.