Repository navigation

Fall back to installed server when GitHub is unreachable #756

Job	Run time
test (ubuntu-latest, 29.4)	26s
test (ubuntu-latest, 28.2)	30s
test (ubuntu-latest, 30.2)	27s
test (ubuntu-latest, 28.1)	20s
test (windows-latest, 28.2)	33s
test (windows-latest, 30.2)	30s
test (ubuntu-latest, snapshot)	20s
test (macos-latest, snapshot)	1m 18s
test (macos-latest, 28.1)	1m 10s
test (windows-latest, snapshot)	45s
test (macos-latest, 30.2)	1m 17s
test (macos-latest, 28.2)	1m 4s
test (windows-latest, 28.1)	31s
test (windows-latest, 29.4)	32s
test (macos-latest, 29.4)	1m 23s
	11m 6s