regexp_unicode_prop.t: Fix up test for Unicode 16.0

This test was assuming that U+0300 (COMBINING GRAVE ACCENT) matches
\p{Inherited}, since it is a combining mark.  However Unicode 16.0 has
gone through such marks and decided that some are limited to actually
just a few scripts, so it is not generally inherited.  (One of those
scripts is Latin, so it is effectively inherited in French, Spanish,
etc.)  But it isn't always inheritied, and so it loses that status, and
the test fails.

I would never have expected this test to be brittle, but so it is.  What
this commit does is to change to another code point that is till
considered Inherited, and the test passes.

Author: khwilliamson

t/re/regexp_unicode_prop.t

@@ -74,7 +74,7 @@ my @CLASSES = (
    'Lowercase Letter'         => ["h", "!H"],
 
     Common                    => ["!i", "3"],
-    Inherited                 => ["!j", '\x{300}'],
+    Inherited                 => ["!j", '\x{31A}'],
 
     InBasicLatin              => ['\N{LATIN CAPITAL LETTER A}'],
     InLatin1Supplement        => ['\N{LATIN CAPITAL LETTER A WITH GRAVE}'],