ExtractPackages.test_change fails with AGP 4.2 on Linux

[mhsmith]

This is probably a bug in this version of Gradle causing the excludes = in the inner scope to overwrite the egg-info exclusion from the outer scope. If so, we can work around it by moving everything to the same scope, or perhaps by avoiding the assignment operator.

[mhsmith]

In CI, this is happening consistently on both Linux, macOS and WIndows. But since AGP 4.2 is now over 2 years old, let's just desupport it in the next Chaquopy release.