Bump version to 0.2.0-alpha.4 #363

Job	Run time
Generate documentation	21s
Benchmark	7m 48s
Check generated C header	1m 7s
Build [ubuntu-latest, 1.63.0, dev, ]	2m 6s
Build [ubuntu-latest, 1.63.0, release, ]	1m 53s
Build [ubuntu-latest, stable, dev, ]	29s
Build [ubuntu-latest, stable, release, ]	51s
Build [macos-latest, 1.63.0, dev, ]	2m 30s
Build [macos-latest, 1.63.0, release, ]	2m 50s
Build [macos-latest, stable, dev, ]	57s
Build [macos-latest, stable, release, ]	1m 11s
Build [ubuntu-latest, stable, dev, --no-default-features]	29s
Lint with clippy	1m 15s
Check code formatting	15s
No-op rebuilds	1m 0s
Test and coverage	3m 9s
Test with release build	2m 57s
Test with address sanitizer	3m 46s
Test with leak sanitizer	2m 59s
	37m 53s

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