Remove useless UB point

As suggested by the review, this is already covered by "metadata must be valid" point.

src/behavior-considered-undefined.md

@@ -49,7 +49,6 @@ undefined behavior, it is *unsound*.
 * Invoking undefined behavior via compiler intrinsics.
 * Executing code compiled with platform features that the current platform
   does not support (see [`target_feature`]), *except* if the platform explicitly documents this to be safe.
-* Performing non-nop coercion on a dangling or unaligned raw pointer.
 * Calling a function with the wrong call ABI or unwinding from a function with the wrong unwind ABI.
 * Producing an [invalid value][invalid-values]. "Producing" a
   value happens any time a value is assigned to or read from a place, passed to