tests: Remove redundant --tap options

Now that TAP output is used by default, passing `--tap` is unnecessary.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Helps: #1619

gio/tests/meson.build

@@ -678,7 +678,6 @@ foreach test_name, extra_args : gio_tests
     env : local_test_env,
     timeout : timeout,
     suite : suite,
-    args : ['--tap'],
     is_parallel : extra_args.get('is_parallel', true),
     depends : extra_args.get('depends', []),
   )