Rollup merge of #72043 - GuillaumeGomez:clean-up-e0569, r=Dylan-DPC

Add missing backtick in E0569 explanation

r? @Dylan-DPC

Author: Dylan-DPC

src/librustc_error_codes/error_codes/E0569.md

@@ -1,5 +1,5 @@
 If an impl has a generic parameter with the `#[may_dangle]` attribute, then
-that impl must be declared as an `unsafe impl.
+that impl must be declared as an `unsafe impl`.
 
 Erroneous code example: