dependencies: don't require full mysql lib for the driver. Reduces installation by ~100MB !!

pkgs/python-packages-overrides.nix

@@ -82,7 +82,7 b' self: super: {'
       pkgs.openssl
     ];
     propagatedBuildInputs = attrs.propagatedBuildInputs ++ [
-      pkgs.mysql.lib
+      pkgs.libmysql
       pkgs.zlib
     ];
   });