[In-Proc] Split `Microsoft.Azure.WebJobs.Script.WebHost.InProc` package reference by target framework

[liliankasem]

The in-proc branch of Core Tools multi-targets net6.0 and net8.0, but uses a single, shared Microsoft.Azure.WebJobs.Script.WebHost.InProc package reference for both target frameworks:

<!-- Current: single reference for both TFMs -->
<PackageReference Include="Microsoft.Azure.WebJobs.Script.WebHost.InProc" Version="4.44.100" />

This means that any update to the in-proc host package requires a new Core Tools build that ships both .NET 6 and .NET 8 bits simultaneously. There is no way to service .NET 8 independently of .NET 6 (or vice-versa).

Considerations

• We will need to update the nuget reference
• We will need to update validateWorkerVersions.ps1
• CI/CD pipelines — Review for any automation that assumes a single InProc host version (e.g., automated version bumps).