test_ukify: raise timeout

With a sufficiently large initrd, the tests take 25 s on my laptop.
Normally, they'd be quicker, but since we use what we find on the
system, we don't control this. Let's raise the timeout to reduce the
chances of a spurious failure.

src/ukify/test/meson.build

@@ -16,5 +16,6 @@ if want_ukify and want_tests != 'false'
              files('test_ukify.py'),
              args: args,
              env : test_env,
+             timeout : 120,
              suite : 'ukify')
 endif