update vyper cfg to include reachability #967

Job	Run time
tests (ubuntu-latest, unit, 3.8)	1m 1s
tests (ubuntu-latest, unit, 3.11)	1m 4s
tests (ubuntu-latest, integration, 3.8)	3m 27s
tests (ubuntu-latest, integration, 3.11)	4m 6s
tests (ubuntu-latest, tool, 3.8)	1m 26s
tests (ubuntu-latest, tool, 3.11)	1m 27s
tests (windows-2022, unit, 3.8)	2m 13s
tests (windows-2022, unit, 3.11)	1m 52s
tests (windows-2022, integration, 3.8)	3m 56s
tests (windows-2022, integration, 3.11)	3m 32s
tests (windows-2022, tool, 3.8)	4m 12s
tests (windows-2022, tool, 3.11)	3m 42s
coverage	18s
	32m 16s

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