Update supported GitHub Enterprise Server versions #4577

Job	Run time
Config export (ubuntu-latest, nightly-latest)	1m 22s
Config export (macos-latest, nightly-latest)	2m 19s
Config export (windows-latest, linked)	1m 47s
Config export (macos-latest, linked)	2m 2s
Config export (windows-latest, nightly-latest)	3m 45s
Config export (ubuntu-latest, linked)	1m 8s
	12m 23s

Provide feedback