update listen gem

Using latest version enables us to run tests against Ruby3.0
guard/listen#490

Gemfile.lock

@@ -57,7 +57,7 @@ GEM
     erubi (1.9.0)
     faker (2.15.1)
       i18n (>= 1.6, < 2)
-    ffi (1.13.1)
+    ffi (1.14.2)
     formatador (0.2.5)
     fuubar (2.5.0)
       rspec-core (~> 3.0)
@@ -84,7 +84,7 @@ GEM
       concurrent-ruby (~> 1.0)
     json (2.3.1)
     jwt (2.2.2)
-    listen (3.2.1)
+    listen (3.4.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     loofah (2.7.0)