chore(deps): bump rack-session in /examples/sinatra/app/src

Bumps [rack-session](https://github.com/rack/rack-session) from 2.0.0 to 2.1.2.
- [Release notes](https://github.com/rack/rack-session/releases)
- [Changelog](https://github.com/rack/rack-session/blob/main/releases.md)
- [Commits](rack/rack-session@v2.0.0...v2.1.2)

---
updated-dependencies:
- dependency-name: rack-session
  dependency-version: 2.1.2
  dependency-type: indirect
...

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

Author: dependabot[bot]

examples/sinatra/app/src/Gemfile.lock

@@ -5,12 +5,13 @@ GEM
     logger (1.6.1)
     mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
-    rack (3.1.12)
+    rack (3.2.6)
     rack-protection (4.1.0)
       base64 (>= 0.1.0)
       logger (>= 1.6.0)
       rack (>= 3.0.0, < 4)
-    rack-session (2.0.0)
+    rack-session (2.1.2)
+      base64 (>= 0.1.0)
       rack (>= 3.0.0)
     rackup (2.1.0)
       rack (>= 3)