Unit testing

chore: pin ubuntu for Python 3.7 availability #452

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Run time

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Job	Run time
code-quality / code-quality (3.8)	38s
code-quality / code-quality (3.9)	42s
build / test-installation	30s
code-quality / code-quality (3.10)	40s
code-quality / code-quality (3.11)	43s
code-quality / code-quality (3.12)	57s
code-quality / code-quality (3.13)	2m 55s
unit-test (3.6)	43s
unit-test (3.7)	33s
unit-test (3.8)	28s
unit-test (3.9)	29s
unit-test (3.10)	28s
unit-test (3.11)	32s
unit-test (3.12)	46s
unit-test (3.13)	2m 59s
	14m 3s