Maintenance: Update dependency puma to v6.4.3

Gemfile.lock

@@ -479,7 +479,7 @@ GEM
     psych (5.1.2)
       stringio
     public_suffix (5.1.1)
-    puma (6.4.2)
+    puma (6.4.3)
       nio4r (~> 2.0)
     pundit (2.4.0)
       activesupport (>= 3.0.0)