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

Author: renovate[bot]

Gemfile.lock

@@ -7,7 +7,7 @@ GIT
 GEM
   remote: https://rubygems.org/
   specs:
-    base64 (0.2.0)
+    base64 (0.3.0)
     bigdecimal (3.1.8)
     bson (5.0.1)
     bson_ext (1.5.1)
@@ -41,8 +41,7 @@ GEM
     method_source (1.1.0)
     mongo (2.21.0)
       bson (>= 4.14.1, < 6.0.0)
-    mustermann (3.0.3)
-      ruby2_keywords (~> 0.0.1)
+    mustermann (3.1.1)
     nenv (0.3.0)
     notiffany (0.1.3)
       nenv (~> 0.1)
@@ -52,10 +51,14 @@ GEM
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
-    rack (2.2.9)
-    rack-protection (3.2.0)
+    rack (3.2.6)
+    rack-protection (4.2.1)
       base64 (>= 0.1.0)
-      rack (~> 2.2, >= 2.2.4)
+      logger (>= 1.6.0)
+      rack (>= 3.0.0, < 4)
+    rack-session (2.1.2)
+      base64 (>= 0.1.0)
+      rack (>= 3.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
     rb-fsevent (0.11.2)
@@ -74,16 +77,17 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
     rspec-support (3.13.1)
-    ruby2_keywords (0.0.5)
     shellany (0.0.1)
-    sinatra (3.2.0)
+    sinatra (4.2.1)
+      logger (>= 1.6.0)
       mustermann (~> 3.0)
-      rack (~> 2.2, >= 2.2.4)
-      rack-protection (= 3.2.0)
+      rack (>= 3.0.0, < 4)
+      rack-protection (= 4.2.1)
+      rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     sorbet-runtime (0.5.11572)
     thor (1.3.2)
-    tilt (2.4.0)
+    tilt (2.8.0)
     tttls1.3 (0.3.3)
       ech_config (~> 0.0.3)
       hpke