Rollup merge of #61776 - JohnTitor:fix-typo-in-error-codes, r=Centril

Fix typos in error_codes

`observedin` should be `observed in`.

src/librustc/error_codes.rs

@@ -1883,7 +1883,7 @@ This pattern should be rewritten. There are a few possible ways to do this:
     # }
     ```
 
-The same applies to transmutes to `*mut fn()`, which were observedin practice.
+The same applies to transmutes to `*mut fn()`, which were observed in practice.
 Note though that use of this type is generally incorrect.
 The intention is typically to describe a function pointer, but just `fn()`
 alone suffices for that. `*mut fn()` is a pointer to a fn pointer.

src/test/ui/explain.stdout

@@ -53,7 +53,7 @@ This pattern should be rewritten. There are a few possible ways to do this:
     let f: extern "C" fn(*mut i32) = transmute(foo as usize); // works too
     ```
 
-The same applies to transmutes to `*mut fn()`, which were observedin practice.
+The same applies to transmutes to `*mut fn()`, which were observed in practice.
 Note though that use of this type is generally incorrect.
 The intention is typically to describe a function pointer, but just `fn()`
 alone suffices for that. `*mut fn()` is a pointer to a fn pointer.