pythonPackages.brotli: don't use deepClone

It's not reproducible

pkgs/development/python-modules/brotli/default.nix

···
     owner = "google";
     repo = pname;
     rev = "v${version}";
-    sha256 = "1rdp9rx197q467ixp53g4cgc3jbsdaxr62pz0a8ayv2lvm944azh";
+    sha256 = "sha256-tFnXSXv8t3l3HX6GwWLhEtgpqz0c7Yom5U3k47pWM7o=";
     # for some reason, the test data isn't captured in releases, force a git checkout
-    deepClone = true;
+    forceFetchGit = true;
   };
 
   dontConfigure = true;