Fix load macros test for PGplot helper macros.

  These macros are not meant to be loaded directly and are part
  of the PGplot.pl macro. This adds them to the borkenMacros
  hash to avoid being loaded during the test.

t/macros/load_macros.t

@@ -34,7 +34,17 @@ my %baseMacros = (
 );
 
 # PG_CAPAmacros.pl is not really broken, but it depends on files that are in the OPL and not in the PG repository.
-my %brokenMacros = ('answerDiscussion.pl' => 1, 'PG_CAPAmacros.pl' => 1);
+# PGplot helper macros Axes.pl, GD.pl, Tikz.pl, and Data.pl are not really broken, but shouldn't be loaded directly.
+# PGplotmacros.pl overrides some default WWplot objects. Loading this causes other test to fail.
+my %brokenMacros = (
+	'answerDiscussion.pl' => 1,
+	'PG_CAPAmacros.pl'    => 1,
+	'Axes.pl'             => 1,
+	'GD.pl'               => 1,
+	'Tikz.pl'             => 1,
+	'Data.pl'             => 1,
+	'PGplotmacros.pl'     => 1,
+);
 
 # Find all macro files inside the $ENV{PG_ROOT}/macros directory.
 my @macro_files;