Update dependency rack to v3.2.6 [SECURITY]

Author: renovate[bot]

bin/template/Gemfile.lock

@@ -162,7 +162,7 @@ GEM
     puma (7.2.0)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (3.1.20)
+    rack (3.1.21)
     rack-livereload (0.6.1)
       rack (>= 3.0, < 3.2)
     rackup (2.3.1)