Fix rakudoc typo (unneeded C inside C)

(This was found because the rendering changed in RAKUAST and that
test complained about this file.)

Author: coke

doc/Language/regexes.rakudoc

@@ -2398,7 +2398,7 @@ C«<.ws>» subrule calls depending on where it occurs in the regex.
     =end code
 
 C<m:s/ photo shop /> acts the same as
-C<m/ photo C«<.ws>» shop <.ws> />. By default, C«<.ws>» makes sure that
+C<m/ photo <.ws> shop <.ws> />. By default, C«<.ws>» makes sure that
 words are separated, so C<a b> and C<^&> will match C«<.ws>» in the
 middle, but C<ab> won't: