Flake.nix corrected main (#5600)

Signed-off-by: Henrik Sjöstrand <henrik.sjostrand@tele2.com>
Co-authored-by: Henrik Sjöstrand <henrik.sjostrand@tele2.com>

flake.nix

@@ -85,6 +85,7 @@
             description = workspaceToml.workspace.package.description;
             homepage = workspaceToml.workspace.package.repository;
             license = licenses.asl20;  # Maps from "Apache-2.0" in Cargo.toml
+            mainProgram = "goose";
           };
         };
 
@@ -117,4 +118,4 @@
         };
       }
     );
-}
+}