[workloads] Add Current to the name of the workload manifest (#80401)
https://github.com/dotnet/sdk/commit/
f5cb7e3c3eb631d13a1bdc6033f399cf8a1ceadb introduced a change that would make `microsoft.net.workload.mono.toolchain` an outdated id in order to work around manifest errors when older previews of the .NET 7 SDK were installed. The unfortunate side effect of this change meant the name of the runtime manifest needs to be changed.
On the main branch, the manifest id will now contain current in the name for the .net version being developed.
Co-authored-by: Ankit Jain <radical@gmail.com>