Remove arch-specific tags from appliance-style and sample images

[jander-msft]

Describe the Problem

The appliance-style (dotnet/monitor and dotnet/aspire-dashboard) and sample (dotnet/samples) images have various tags for describing the product version, the architecture, and distro of the image. While distro information has been removed in newer releases, the architecture and product version information remains. The tag listing for these images can be intimidating due to the matrix of possibilities and may lead to choice paralysis or confusion as to which tag should be used.

Upon further reflection, the tag matrix can be greatly simplified if the arch-specific tags are removed or undocumented. An example simplification in this manner is described for the sample images in #5918. Using dotnet/monitor:8 Ubuntu Chiseled as another example, the tag listing would be simplified from:

8.0.4-ubuntu-chiseled-amd64, 8.0-ubuntu-chiseled-amd64, 8-ubuntu-chiseled-amd64, 8.0.4-ubuntu-chiseled, 8.0-ubuntu-chiseled, 8-ubuntu-chiseled, 8.0.4, 8.0, 8, latest

to

8.0.4-ubuntu-chiseled, 8.0-ubuntu-chiseled, 8-ubuntu-chiseled, 8.0.4, 8.0, 8, latest

Describe the Solution

• For dotnet/aspire-dashboard:8* images, all arch-specific tags are to be undocumented to prevent breaking changes in current usage.
• For dotnet/monitor:9* images, all arch-specific tags are to be removed since these are unlikely to be used at this point.
• For dotnet/monitor:8* and lower version images, all arch-specific tags are to be undocumented to prevent breaking changes in current usage.
• For dotnet/samples images, all arch-specific tags are to be removed.

For dotnet/monitor/base, all arch-specific tags are to remain since this is a base image used for adding extensions upon it, which may require native dependencies or may have native entrypoints.

Additional Context

The arch-specific tags are largely useful for images that are meant to be used as base images upon which derivative images are produced, especially if native dependencies are added in the deriving image. Given that the appliance-style and sample images are intended to be used as-is (not expected to be derived), the arch-specific tags do not provide much value. The assumption is that the vast majority use case is that users will use the manifest tags as-is without needing to further specify the platform. If needed, users can specify platform information on container tooling (such as docker run --platform linux/amd64 or FROM --platform linux/amd64 within Dockerfiles) to specify which architecture should be used.