chore: update gitignore for mise local config and remove nixpacks

Generated-by: aiautocommit

Author: iloveitaly

.gitignore

@@ -11,8 +11,7 @@ __pycache__
 env/*local.*
 env/host.sh
 mise.*local.toml
-
-.nixpacks
+mise.*local.lock
 
 # TODO this should really be redirected to a tmp/ directory
 .coverage