direnv: use flake

.envrc

@@ -1,15 +1,10 @@
 if [ -e .envrc-override ]; then
-    # This env file will trump lorri, if present.
+    # This env file will trump nix-direnv, if present.
     source_env .envrc-override
-elif type lorri &>/dev/null; then
-    eval "$(lorri direnv)"
 else
-    # Fall back to using direnv's builtin nix support
-    # to prevent bootstrapping problems.
-    # It's definitely better to use lorri, because direnv won't
-    # be fast like this.
-    use nix
+    # Requires nix-direnv
+    use flake
 fi
 
-# Source a user-specific config in ./.envrc-local
+# Source a user-specific config in .envrc-local
 source_env_if_exists .envrc-local