Fix ∘'s name

it's either `infix:<∘>` or `infix ∘`, not `infix <∘>`

Author: zoffixznet

doc/Language/operators.pod6

@@ -1169,7 +1169,7 @@ L<Buf|/type/Buf>, a combined buffer is returned.
 
     say 'ab' ~ 'c';     # OUTPUT: «abc␤»
 
-=head2 infix C«<∘>»
+=head2 infix C«∘»
 
     multi sub infix:<∘>()
     multi sub infix:<∘>(&f)