test: Dist the platform shaper test data

For builds from release tarballs, the tests fail in the DirectWrite and
Uniscribe tests when these platform shapers are enabled, since the data files
were not found in the source tree, when building with Meson at least.

Fix this by dist'ing the platform shaper test data files.

test/shape/data/in-house/Makefile.sources

@@ -71,5 +71,15 @@ TESTS = \
 	tests/zero-width-marks.tests \
 	$(NULL)
 
+if HAVE_CORETEXT
+TESTS += tests/coretext.tests
+endif
+if HAVE_DIRECTWRITE
+TESTS += tests/directwrite.tests
+endif
+if HAVE_UNISCRIBE
+TESTS += tests/uniscribe.tests
+endif
+
 DISABLED_TESTS = \
 	$(NULL)