Bump rackup from 1.0.0 to 2.1.0

Bumps [rackup](https://github.com/rack/rackup) from 1.0.0 to 2.1.0.
- [Release notes](https://github.com/rack/rackup/releases)
- [Commits](rack/rackup@v1.0.0...v2.1.0)

---
updated-dependencies:
- dependency-name: rackup
  dependency-type: indirect
  update-type: version-update:semver-major
...

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

Gemfile.lock

@@ -202,12 +202,11 @@ GEM
       rouge
       sprockets (>= 3)
       sprockets-rails
-    govuk_sidekiq (8.0.1)
+    govuk_sidekiq (9.0.0)
       gds-api-adapters (>= 19.1.0)
       govuk_app_config (>= 1.1)
-      redis (< 5)
-      redis-namespace (~> 1.6)
-      sidekiq (~> 6.5, >= 6.5.12)
+      redis-client (>= 0.22.2)
+      sidekiq (~> 7.0, < 8)
     govuk_test (4.1.0)
       brakeman (>= 5.0.2)
       capybara (>= 3.36)
@@ -542,18 +541,18 @@ GEM
     pundit (2.4.0)
       activesupport (>= 3.0.0)
     racc (1.8.1)
-    rack (2.2.9)
+    rack (3.1.7)
     rack-attack (6.7.0)
       rack (>= 1.0, < 4)
     rack-proxy (0.7.7)
       rack
-    rack-session (1.0.2)
-      rack (< 3)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
     rack-test (2.1.0)
       rack (>= 1.3)
-    rackup (1.0.0)
-      rack (< 3)
-      webrick
+    rackup (2.1.0)
+      rack (>= 3)
+      webrick (~> 1.8)
     rails (7.2.1)
       actioncable (= 7.2.1)
       actionmailbox (= 7.2.1)
@@ -595,9 +594,8 @@ GEM
     rdoc (6.7.0)
       psych (>= 4.0.0)
     recursive-open-struct (1.2.2)
-    redis (4.8.1)
-    redis-namespace (1.11.0)
-      redis (>= 4)
+    redis-client (0.22.2)
+      connection_pool
     regexp_parser (2.9.2)
     reline (0.5.10)
       io-console (~> 0.5)
@@ -678,10 +676,12 @@ GEM
       sentry-ruby (~> 5.19.0)
       sidekiq (>= 3.0)
     shoulda-context (2.0.0)
-    sidekiq (6.5.12)
-      connection_pool (>= 2.2.5, < 3)
-      rack (~> 2.0)
-      redis (>= 4.5.0, < 5)
+    sidekiq (7.3.2)
+      concurrent-ruby (< 2)
+      connection_pool (>= 2.3.0)
+      logger
+      rack (>= 2.2.4)
+      redis-client (>= 0.22.2)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
@@ -715,7 +715,7 @@ GEM
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    webrick (1.8.1)
+    webrick (1.8.2)
     websocket (1.2.11)
     websocket-driver (0.7.6)
       websocket-extensions (>= 0.1.0)