Bump rack from 2.2.17 to 2.2.18 in /examples

(cherry picked from commit 0d3e345)

Author: chadlwilson

examples/rails7/Gemfile.lock

@@ -127,7 +127,7 @@ GEM
       date
       jar-dependencies (>= 0.1.7)
     racc (1.8.1-java)
-    rack (2.2.17)
+    rack (2.2.18)
     rack-session (1.0.2)
       rack (< 3)
     rack-test (2.2.0)

examples/sinatra/Gemfile.lock

@@ -6,7 +6,7 @@ GEM
     jruby-rack (1.2.5)
     mustermann (3.0.4)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.17)
+    rack (2.2.18)
     rack-protection (3.2.0)
       base64 (>= 0.1.0)
       rack (~> 2.2, >= 2.2.4)