When exporting to Android with net6.0 as target framework, it proceeds with no errors but game crashes

[MohammadAlkurd]

Tested versions

4.2.stable official and 4.3.dev

System information

linux pop os 22.04LTS

Issue description

when opening a godot project made in 4.1 or earlier there is no override for the targetframework for the android build here is an image as an example
of a brand new project made on 4.2

here is an example of an old project updated to 4.3 and previously updated to 4.2

the error is as descriped in this image of adb logcat on an emulator

after that the game just crashes

i suggest adding a warning or an error when building dotnet android games with dotnet version 6.0 or older i might try adding that myself as a practice one enough people agree but if its possible that another solution is present then i cant really help

Steps to reproduce

opening a project made in godot 4.1 and updating it to 4.2 does not change target framework for android so if u had dotnet 6 installed it wont warn you to update to .net 7 for android

Minimal reproduction project (MRP)

any project with a single c# script attached to node should do the trick with .net 6 in target framework

[raulsntos]

We were discussing upgrading the TFM automatically for existing projects opened with a newer Godot version (like we already do for the Godot SDK).

• C#: Upgrade the platform-specific TargetFramework version automatically #82927.

Checking that the TFM is supported when exporting to Android is something that was suggested during the 4.2 development. I thought that #82762 and godotengine/godot-docs#8227 would be enough for now, since the export is marked experimental anyway.