Improve how the cross-target libclrjit is excluded from RuntimeList.xml

This approach has shortcomings:

https://github.com/dotnet/core-setup/blob/32cdcac88710b83a83c25dd1e2be946e3c180931/tools-local/tasks/CreateFrameworkListFile.cs#L107-L117

1. We don't know that all files that have this impact on self-contained publish will have `_` in the name of the dir.
2. It can't be tweaked by build logic.

I think a better way to do this is changing `runtime/` to `runtimes/linux-arm/` in `TargetFilePrefixes`.

(Details why files like this shouldn't be in the runtime list at https://github.com/dotnet/core-setup/issues/7039.)

Related: https://github.com/dotnet/core-setup/issues/5105. Another example usage of improved/generalized filtering infra.

Start with the linked CreateFrameworkListFile.cs code around lines 107-117 and inspect how TargetFilePrefixes produces RuntimeList.xml. Review issues 7039 and 5105 for the filtering requirements; done means cross-target libclrjit is excluded without relying on directory underscores and the filtering remains configurable by build logic.

Written by the indexing model from the issue text.