Launchpad should be able to pin m# MCR Versions

[james-nesbitt]

IDEA-2351 / PRODENG-3099

Several consumers have issues with MCR installation with install.sh/launchpad as they are unable to pin the MCR .m# versions. The issue is that a consumer can test one version of MCR but then be given a different version when moving to production, if an m# version release exists.
Note that it is Mirantis policy that MCR .m# versions should be considered critical urgency patches (invalidating previous compliance results) and non-breaking. No consumer should install a replaced m# version, when a new one is available.

For launchpad, there is no way to allow m# install pinning, as install.sh doesn't support it. Install.sh is not meant to be an all use-case installer, but rather a best-practice installer, and will not be updated to handle this requirement.

[james-nesbitt]

The consensus in Mirantis is to follow the newer approaches for installing MCR25, which does away with the need for the install.sh script.
While install.sh is flexible cross platform, it was never a good match for launchpad as it doesn't give any feedback for embedding - making it hard to tell what has failed/succeeded. At the same time, MCR25 installations are much easier, with no additional complexity required for dependency matching between MCR and Containerd/Runc components.
We should be able to install with just repos & package-management.

[james-nesbitt]

This effort will start soon