Mark Test::is_approx as removed in 2023.09

Author: lizmat

doc/Type/Test.rakudoc

@@ -192,7 +192,7 @@ isnt $a, Nil, 'Nil should not survive being put in a container';
 
     multi sub is_approx(Mu $got, Mu $expected, $desc = '')
 
-B<NOTE>: Deprecated as of version 6.d. Please use C<is-approx> instead.
+B<NOTE>: Removed with Rakudo release 2023.09.  Please use C<is-approx> instead
 
 Checks if result and the expected value are approximately equal to a certain
 degree of tolerance, fixed to 1e-5 or one-millionth of the expected value is its
@@ -202,9 +202,8 @@ value is less than that.
 use Test;
 is_approx(1e4, 1e4-1e-6, "Real close"); # OUTPUT: «ok 1 - Real close␤»
 
-(This will print also a deprecation notice if you're using 6.d)
-
-
+(This will print also a deprecation notice when using a Rakudo release
+-before 2023.09)
 
 =head2 sub is-approx