Revert code changes for Workaround for attributes.pm breakage

This partially reverts ebb1d9c.

The real fix for this problem has now been committed, so the workaround
can be reverted, leaving the tests.

locale.c

@@ -5173,15 +5173,6 @@ Perl_init_i18nl10n(pTHX_ int printwarn)
     /* Done with finding the locales; update the auxiliary records */
     new_LC_ALL(NULL);
 
-#  if defined(USE_POSIX_2008_LOCALE) && defined(USE_LOCALE_NUMERIC)
-
-    /* This is a temporary workaround for #20155, to avoid issues where the
-     * global locale wants a radix different from the per-thread one.  This
-     * restores behavior for LC_NUMERIC to what it was before a7ff7ac. */
-    posix_setlocale(LC_NUMERIC, "C");
-
-#  endif
-
     for (i = 0; i < NOMINAL_LC_ALL_INDEX; i++) {
         Safefree(curlocales[i]);
     }