refactor(noctalia): move config to prdlk/noctalia external

dot_config/noctalia/config.toml

@@ -1,9 +0,0 @@
-# Noctalia hand-written config (merged under the GUI's
-# ~/.local/state/noctalia/settings.toml, which is not managed).
-# Reference: https://docs.noctalia.dev/noctalia/configuration/
-
-[shell]
-# Built-in polkit authentication agent: the Umbriel session starts nothing but
-# Noctalia, so without it pkexec and other privileged actions fail with "no
-# agent is available". Only one agent can register per session.
-polkit_agent = true