chore(deps): update dependency sinatra to v4 [security]

Gemfile.lock

@@ -137,7 +137,7 @@ GEM
       eventmachine (~> 1.0, >= 1.0.4)
       rack (>= 1, < 3)
     thor (1.3.2)
-    tilt (2.5.0)
+    tilt (2.6.0)
     tty-pager (0.14.0)
       strings (~> 0.2.0)
       tty-screen (~> 0.8)