Update crate-attr.md

Co-authored-by: Vadim Petrochenkov <[email protected]>

Author: jyn514

src/doc/unstable-book/src/compiler-flags/crate-attr.md

@@ -11,6 +11,6 @@ To inject multiple attributes, pass `-Z crate-attr` multiple times.
 
 Formally, the expansion behaves as follows:
 1. The crate is parsed as if `-Z crate-attr` were not present.
-2. The attributes in `-Z crate-attr` are parsed and validated.
+2. The attributes in `-Z crate-attr` are parsed.
 3. The attributes are injected at the top of the crate root.
 4. Macro expansion is performed.