[meson] increase subset tests timeout

https://github.com/harfbuzz/harfbuzz/runs/676665822#step:6:570

fails because meson runs the tests in parallel, correct fix will be making the tests smaller

test/subset/meson.build

@@ -37,8 +37,7 @@ foreach t : tests
     ],
     # as the tests are ran concurrently let's raise acceptable time here
     # ideally better to break and let meson handles them in parallel
-    timeout: 140,
+    timeout: 200,
     workdir: join_paths(meson.current_build_dir(), '..', '..'),
   )
 endforeach
-