Use stable-haskell github repo

Author: hamishmack

lazy-inputs/ghc9103/flake.lock

@@ -4,7 +4,7 @@
   inputs = {
     ghc9103 = {
       flake = false;
-      url = "git+https://github.com/ghc/ghc?rev=3f4d7d38b9661435bdde981451ac50c4335ed090&submodules=1";
+      url = "git+https://github.com/stable-haskell/ghc?ref=ghc-9.10.3-iog&submodules=1";
     };
   };