Remove 2nd const

It was causing two build-time warnings.

Corrects patch originally submitted in
#18726.

toke.c

@@ -93,8 +93,8 @@ Individual members of C<PL_parser> have their own documentation.
     (SvTYPE(sv) >= SVt_PVNV \
     && ((XPVIV*)SvANY(sv))->xiv_u.xivu_eval_seen)
 
-static const char const ident_too_long[] = "Identifier too long";
-static const char const ident_var_zero_multi_digit[] = "Numeric variables with more than one digit may not start with '0'";
+static const char ident_too_long[] = "Identifier too long";
+static const char ident_var_zero_multi_digit[] = "Numeric variables with more than one digit may not start with '0'";
 
 #  define NEXTVAL_NEXTTOKE PL_nextval[PL_nexttoke]