Add support for net8

[martinbryant]

This PR closes #

The changes in this PR are as follows:

• Added net8 support for Functions runtime
• Added net8 static member
• Added unit tests for web app deploy

I have read the contributing guidelines and have completed the following:

• [x] Tested my code end-to-end against a live Azure subscription.
• [x] Updated the documentation in the docs folder for the affected changes.
• [x] Written unit tests against the modified code that I have made.
• [x] Updated the release notes with a new entry for this PR.
• [x] Checked the coding standards outlined in the contributions guide and ensured my code adheres to them.

If I haven't completed any of the tasks above, I include the reasons why here:

Below is a minimal example configuration that includes the new features, which can be used to deploy to Azure:

[ninjarobot]

@martinbryant changes look good, thanks for including tests. Please address the formatting issues so the PR passes all checks.

[ninjarobot]

@martinbryant changes look good, thanks for including tests. Please address the formatting issues so the PR passes all checks.

@martinbryant I ran dotnet fantomas -r src on your PR branch and will merge today.

[ninjarobot]

@martinbryant thanks for the contribution, this is included in the 1.8.2 release available on nuget.