build(deps): bump sinatra in /test/preflight/fixtures/example-buildpack

Bumps [sinatra](https://github.com/sinatra/sinatra) from 4.1.1 to 4.2.0.
- [Changelog](https://github.com/sinatra/sinatra/blob/main/CHANGELOG.md)
- [Commits](sinatra/sinatra@v4.1.1...v4.2.0)

---
updated-dependencies:
- dependency-name: sinatra
  dependency-version: 4.2.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

test/preflight/fixtures/example-buildpack/Gemfile

@@ -15,4 +15,4 @@ gem "rackup"
 # https://bugs.ruby-lang.org/issues/17303
 gem "puma"
 
-gem "sinatra", "~> 4.1"
+gem "sinatra", "~> 4.2"

test/preflight/fixtures/example-buildpack/Gemfile.lock

@@ -9,24 +9,24 @@ GEM
     puma (6.5.0)
       nio4r (~> 2.0)
     rack (3.2.1)
-    rackup (2.2.1)
-      rack (>= 3)
-    rack-protection (4.1.1)
+    rack-protection (4.2.0)
       base64 (>= 0.1.0)
       logger (>= 1.6.0)
       rack (>= 3.0.0, < 4)
     rack-session (2.1.1)
       base64 (>= 0.1.0)
       rack (>= 3.0.0)
+    rackup (2.2.1)
+      rack (>= 3)
     ruby2_keywords (0.0.5)
-    sinatra (4.1.1)
+    sinatra (4.2.0)
       logger (>= 1.6.0)
       mustermann (~> 3.0)
       rack (>= 3.0.0, < 4)
-      rack-protection (= 4.1.1)
+      rack-protection (= 4.2.0)
       rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
-    tilt (2.1.0)
+    tilt (2.6.1)
 
 PLATFORMS
   ruby
@@ -35,7 +35,7 @@ DEPENDENCIES
   puma
   rack
   rackup
-  sinatra (~> 4.1)
+  sinatra (~> 4.2)
 
 BUNDLED WITH
    2.6.1