Multi-targeting host build to create .NET 8 artifacts

[fabiocav]

Update the in-proc host to add a .NET 8 target.

Feature branch: https://github.com/Azure/azure-functions-host/tree/feature/in-proc8

Tasks

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1. Review and merge PR [pack] Use dotnet common artifacts output #9858
2. Create feature branch (from in-proc) for new .NET 8 changes
3. Backport 9858 to in-proc (PR [in-proc backport] Use dotnet common artifacts output (#9858) #10079)
4. Update runtime assembly files in dev and in-proc branch
5. Address any issues and failures in .NET 8 in-proc branch

Test Failures

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1. DependencyTests - Need to update file path (different test for net6.0 vs net8.0)
2. RpcWorkerConfigFactoryTests - Unexpected process count (my machines core count is 16 which is impacting this test, might be fine in the CI pipeline)
3. ProxyFunctionDescriptorProviderTests - Call is ambiguous between the following methods or properties
4. ProxyFunctionDescriptorTests - Call is ambiguous between the following methods or properties
5. WebFunctionsManagerTests - MoqException: IConfiguration
6. DefaultDependencyValidatorTests - DryIoc.ContainerException
7. LoggingConfigurationTests - DryIoc.ContainerException
8. NullReference and ArgumentNull exceptions
9. TFM error
10. FunctionAssemblyLoadContextEndToEndTests failures
11. Missing debug_net6.0 dir in pipeline

[fabiocav]

Closing as resolved.