playground/TestShop fails to run after restore.cmd - Microsoft.AspNetCore.App 8.0.0 runtime missing from local .dotnet

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

After running restore.cmd, the following runtimes are missing from the local .dotnet folder:
- Microsoft.NETCore.App 8.0.0
- Microsoft.AspNetCore.App 8.0.0

The first error appears immediately:

Framework: 'Microsoft.NETCore.App', version '8.0.0' (x64)
.NET location: C:\Dev\aspire\.dotnet
The following frameworks were found:
10.0.5 at [C:\Dev\aspire\.dotnet\shared\Microsoft.NETCore.App]

After manually installing Microsoft.NETCore.App 8.0.0, a second error appears:

Framework: 'Microsoft.AspNetCore.App', version '8.0.0' (x64)
.NET location: C:\Dev\aspire\.dotnet
The following frameworks were found:
10.0.5 at [C:\Dev\aspire\.dotnet\shared\Microsoft.AspNetCore.App]

### Expected Behavior

restore.cmd should install all runtimes required to run the playground projects,
including Microsoft.NETCore.App 8.0.0 and Microsoft.AspNetCore.App 8.0.0,
since net8.0 is the repo's DefaultTargetFramework defined in eng/Versions.props.

Alternatively, the DefaultTargetFramework in eng/Versions.props could be updated
to net10.0, so that restore.cmd only needs to provide the .NET 10 runtime, which it already installs today.

### Steps To Reproduce

_No response_

### Exceptions (if any)

_No response_

### .NET Version info

_No response_

### Anything else?

_No response_