Update sinatra to version 4.2.1

Author: depfu[bot]

Gemfile.lock

@@ -65,7 +65,7 @@ GEM
     rack (3.2.3)
     rack-cors (2.0.2)
       rack (>= 2.0.0)
-    rack-protection (4.2.0)
+    rack-protection (4.2.1)
       base64 (>= 0.1.0)
       logger (>= 1.6.0)
       rack (>= 3.0.0, < 4)
@@ -78,11 +78,11 @@ GEM
     ruby2_keywords (0.0.5)
     shotgun (0.9.2)
       rack (>= 1.0)
-    sinatra (4.2.0)
+    sinatra (4.2.1)
       logger (>= 1.6.0)
       mustermann (~> 3.0)
       rack (>= 3.0.0, < 4)
-      rack-protection (= 4.2.0)
+      rack-protection (= 4.2.1)
       rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     tilt (2.6.1)