main: remove recusion limit exception

we now require rust > 1.70 so this is no longer needed
(tested with 1.75 and 1.81)

src/main.rs

@@ -1,6 +1,3 @@
-// recursion limit can be removed when we bump rustc requirement to 1.70
-#![recursion_limit = "256"]
-
 use anyhow::Result;
 
 mod args;