.NET 8 `$(TargetFramework)` Removal

[jonathanpeppers]

Android framework version

net8.0-android

Affected platform version

.NET 8

Description

.NET 8 is out of support for mobile (note that LTS/STS doesn't apply to mobile):

• https://aka.ms/maui-support-policy

We would recommend updating to .NET 9, which will remain in support ~6 months after .NET 10 is released.

This repo has been deploying NuGet packages with:

• net8.0-android
• net10.0-android (better NativeAOT / trimming support)

In the near future, the NuGet packages built in this repository will stop supporting the net8.0-android target framework, and target net9.0-android instead.

This change has already landed in the main branch:

• Update the versions used to be .NET 9 and 10  #1169

To reduce disruption, we've been shipping updates out of the net8.0 branch:

• https://github.com/dotnet/android-libraries/tree/net8.0

If you want to continue using .NET 8 for Android, you can simply no longer update AndroidX, Google Play Services, or other packages produced by this repository.

If you are already using net9.0-android in your project, no action needed!

Thanks!