feat: Migrate to gradle 8.

[helpisdev]

No description provided.

[Robert01101101]

I get this error with this fix:

One or more plugins require a higher Android NDK version.
Fix this issue by adding the following to C:\Users\user\AndroidStudioProjects\flutter_app\android\app\build.gradle:
android {
ndkVersion "26.2.11394342"
...
}

While I can still build and run the app despite this error, it seems that AlceoMazza's fix doesn't have this issue while also migrating to gradle 8

#95