Rollup merge of rust-lang#146584 - cyrgani:error-codes-macro, r=GuillaumeGomez

remove duplicated columns from `rustc_error_code::error_codes!`

Possible because of rust-lang#146308 ~~, but currently still blocked on the next stage0 bump~~.

Author: JonathanBrouwer

compiler/rustc_error_codes/src/error_codes/E0773.md

@@ -1,4 +1,4 @@
-#### this error code is no longer emitted by the compiler.
+#### Note: this error code is no longer emitted by the compiler.
 
 This was triggered when multiple macro definitions used the same
 `#[rustc_builtin_macro(..)]`. This is no longer an error.