scripts: Make generate_source.py look harder for vk.xml #658

Job	Run time
generate_source	22s
reuse	10s
chromium	1m 39s
windows-arm64	1m 22s
android (armeabi-v7a)	54s
android (arm64-v8a)	1m 4s
build_and_test (Debug, ubuntu-20.04)	1m 15s
build_and_test (Debug, ubuntu-22.04)	1m 25s
build_and_test (Debug, windows-latest)	1m 26s
build_and_test (Debug, macos-latest)	49s
build_and_test (Release, ubuntu-20.04)	1m 33s
build_and_test (Release, ubuntu-22.04)	1m 34s
build_and_test (Release, windows-latest)	3m 13s
build_and_test (Release, macos-latest)	1m 22s
	18m 8s

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