feat: Removes GHES 3.8

BREAKING CHANGE: remove GHES 3.8

Author: nickfloyd

cache/ghes-3.8.json

@@ -5,7 +5,6 @@ module.exports = {
     ["ghes-3.10"]: require("./generated/ghes-3.10.json"),
     ["ghes-3.11"]: require("./generated/ghes-3.11.json"),
     ["ghes-3.12"]: require("./generated/ghes-3.12.json"),
-    ["ghes-3.8"]: require("./generated/ghes-3.8.json"),
     ["ghes-3.9"]: require("./generated/ghes-3.9.json"),
     ["github.ae"]: require("./generated/github.ae.json"),
   },