Added cacheSize in ReserveCache API request

src/internal/cacheUtils.ts

@@ -123,3 +123,10 @@ export function assertDefined<T>(name: string, value?: T): T {
 
   return value
 }
+
+export function isGhes(): boolean {
+  const ghUrl = new URL(
+      process.env["GITHUB_SERVER_URL"] || "https://github.com"
+  );
+  return ghUrl.hostname.toUpperCase() !== "GITHUB.COM";
+}