Core Tools .NET 9 Changes

[aishwaryabh]

Issue describing the changes in this PR

resolves #2560

Adding .NET 9 support for the func init command by adding .NET 9 as a supported TFM
When released, this commit should be released with the following changes as well:

• Tooling feed updates to support .NET 9 azure-functions-tooling-feed#549
• Add net9 to dotnet isolated project templates config azure-functions-templates#1542

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes do not need to be backported to a previous version
  • Otherwise: Backport tracked by issue/PR #issue_or_pr
• I have added all required tests (Unit tests, E2E tests)

[kshyju]

Let's ensure that the following two use cases are functioning correctly for net9.0.

1. The init action works for Docker file use case.

   func init --worker-runtime dotnet-isolated --target-framework net9.0 --docker

2. The publish action is also working.

[aishwaryabh]

Followed up with Shyju regarding testing out dockerfile and publish command and we will address that in this issue once the linux images have been published: Docker images for .NET 9 - Core tools · Issue #2590 · Azure/azure-functions-dotnet-worker (github.com)