Update 8.* aspire-dashboard and monitor mariner images to 3.0

[MichaelSimons]

Once Azure Linux 3.0 is released, the 8.* aspire-dashboard and monitor mariner images should be updated to it. These images are appliance images that have either no distro tags (aspire) or floating distro tags (monitor) which means updating the OS version is intended. Given there the branding change between cbl-mariner and azurelinux, the recommendation is to add azurelinux tags for monitor and undocument the existing mariner tags (they will still be updated/produced, just not documented).

[lbussell]

[Triage] Related: #5467

The distro used in these images can be updated since they're "Appliance" style images and don't guarantee a specific distro version. We do this for Alpine Linux and .NET Monitor already. We should capture this policy decision in our documentation for future reference.

Since Mariner 2.0 may be EOL before .NET 8.0 is EOL, we will likely have to do this. It's just a matter of when - whether it's immediately or closer to the EOL of Mariner 2.0. We should work with the Aspire and Monitor teams to ensure that we have CI coverage for Azure Linux 3.0 before its release.

[jander-msft]

.NET Monitor runs tests on Helix and would require dotnet/dotnet-buildtools-prereqs-docker#1005 to be completed first before adding Azure Linux 3.0 to its test matrix.