[tet.py] Remove `common_toolkit` to `utility`. #691

Job	Run time
basic test except svd and qr	1m 45s
trigger for building wheels	0s
generate README.md for python package	0s
build pure python wheels	0s
build PyTAT wheels	0s
create github release	0s
upload wheels to pypi	0s
	1m 45s

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