Build error: MSB4057: The target "CreatePkg" does not exist in the project.

### Description

Hi, Homebrew maintainer here.

If this is not the correct repository for this issue, please feel free to move it.

When trying to build dotnet 10, we are running into an issue where the "CreatePkg" target does not exist in the project, and I couldn't find a way to reliably skip the build of the installer.

### Reproduction Steps

I was able to get it to successfully build by injecting a property into the files `src/aspnetcore/Directory.Build.props` and `src/runtime/Directory.Build.props`.

```
true
```

### Expected behavior

For the installer target to be skipped unless requested, or be able to be skipped with a build flag.

### Actual behavior

-

### Regression?

This build error was not seen on dotnet 9 releases.

### Known Workarounds

_No response_

### Configuration

Building 10.0.101 on self-hosted macOS runners.

### Other information

Related PR: https://github.com/Homebrew/homebrew-core/pull/254079