meson: Use 'tap' test protocol by default

Meson supports tap protocol results parsing, allowing us to track better
the tests that are running (and the ones that are actually skipped) without
manually parsing the test output.

However this also implies that using the verbose mode for a test doesn't
show its output by default (unless there are failures).

gio/tests/meson.build

@@ -1035,6 +1035,7 @@ foreach test_name, extra_args : gio_tests
   endif
 
   test(test_name, exe,
+    protocol : extra_args.get('protocol', test_protocol),
     env : local_test_env,
     timeout : timeout,
     suite : suite,
@@ -1059,6 +1060,7 @@ foreach test_name, extra_args : python_tests
   test(
     test_name,
     python,
+    protocol : extra_args.get('protocol', test_protocol),
     depends: depends,
     args: ['-B', files(test_name)],
     env: test_env,