graalvm-jdk: update livecheck

Co-authored-by: Sam Ford <1584702+samford@users.noreply.github.com>

Casks/g/graalvm-jdk.rb

@@ -13,7 +13,7 @@ cask "graalvm-jdk" do
 
   livecheck do
     url "https://www.oracle.com/java/technologies/downloads/"
-    regex(/graalvm\s+for\s+jdk\s+(\d+(?:\.\d+)+)/i)
+    regex(/GraalVM\s+for\s+JDK\s+v?(\d+(?:\.\d+)*)\s+downloads/im)
   end
 
   artifact "graalvm-jdk-#{version}+12.1", target: "/Library/Java/JavaVirtualMachines/graalvm-#{version.major}.jdk"