Remove deprecated OpaquePointer reference #4602 (#4612)

Author: horberlan

doc/Language/faq.rakudoc

@@ -808,10 +808,6 @@ as an ordinary object or ignore it in sink context.
 A L<C<Failure>|/type/Failure> returns C<False> from a C<defined> check, and you can extract
 the exception with the C<exception> method.
 
-=head2 What's the difference between C<Pointer> and C<OpaquePointer>?
-
-C<OpaquePointer> is deprecated and has been replaced with C<Pointer>.
-
 =head2 You can have colonpairs in identifiers. What's the justification?
 
 L<Identifiers can include colon pairs, which become part of their name|/language/syntax#Identifiers>.