Merge pull request #1257 from reactjs/dependabot/bundler/rack-2.2.6.3

Bump rack from 2.2.6.2 to 2.2.6.3

Author: ahangarha

Gemfile.lock

@@ -165,7 +165,7 @@ GEM
       pry (~> 0.10)
     public_suffix (4.0.6)
     racc (1.6.1)
-    rack (2.2.6.2)
+    rack (2.2.6.3)
     rack-test (2.0.2)
       rack (>= 1.3)
     rails (6.0.2.1)