rakudo-star: Fix hash extraction (#3443)

also changed autoupdate#️⃣regex

bucket/rakudo-star.json

@@ -28,7 +28,7 @@
         },
         "hash": {
             "url": "$url.checksums.txt",
-            "regex": "$basename\\)\\s+=\\s+$sha256"
+            "regex": "SHA256\\s+$sha256"
         }
     }
 }