[CI] Remove unused scripts and workflows #4

Job	Run time
target-machine	2s
prepare-test-matrix	1m 0s
check-formatting (716762d44f8e61fc16c10f30311ffdfba91c0a63)	1s
regression-tests (716762d44f8e61fc16c10f30311ffdfba91c0a63, default)	1d 0h 0m 1s
	1d 0h 1m 4s

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