Bump sinatra from 4.0.0 to 4.1.0 in /examples/sinatra

Bumps [sinatra](https://github.com/sinatra/sinatra) from 4.0.0 to 4.1.0.
- [Changelog](https://github.com/sinatra/sinatra/blob/main/CHANGELOG.md)
- [Commits](sinatra/sinatra@v4.0.0...v4.1.0)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

examples/sinatra/Gemfile.lock

@@ -115,9 +115,10 @@ GEM
     public_suffix (6.0.1)
     puma (6.4.3)
       nio4r (~> 2.0)
-    rack (3.1.7)
-    rack-protection (4.0.0)
+    rack (3.1.8)
+    rack-protection (4.1.0)
       base64 (>= 0.1.0)
+      logger (>= 1.6.0)
       rack (>= 3.0.0, < 4)
     rack-session (2.0.0)
       rack (>= 3.0.0)
@@ -130,10 +131,11 @@ GEM
       faraday (>= 0.17.5, < 3.a)
       jwt (>= 1.5, < 3.0)
       multi_json (~> 1.10)
-    sinatra (4.0.0)
+    sinatra (4.1.0)
+      logger (>= 1.6.0)
       mustermann (~> 3.0)
       rack (>= 3.0.0, < 4)
-      rack-protection (= 4.0.0)
+      rack-protection (= 4.1.0)
       rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     tilt (2.4.0)