Prepare 0.4.0 #807

Job	Run time
Ktlint	31s
Clippy (stable) (ubuntu-latest)	52s
Clippy (-Zbuild-std)	31s
Clippy (stable) (macos-latest)	27s
Clippy (MSRV) (ubuntu-latest)	2m 2s
Check for documentation errors	16s
Clippy (stable) (windows-latest)	1m 25s
Rustfmt	5s
Clippy (MSRV) (macos-latest)	1m 47s
Clippy (MSRV) (windows-latest)	2m 41s
Check semver compatibility	17s
Test (ubuntu-latest)	16s
Test (Android)	3m 48s
Test (macos-latest)	20s
Test (windows-latest)	1m 39s
Test (FreeBSD)	2m 39s
Verify Android artifacts	1m 1s
	20m 37s

Provide feedback