Add tsort as a runtime dependency to railties

TSort is getting removed: https://bugs.ruby-lang.org/issues/21442

Railties mainly uses tsort to find the order in which initializers are supposed to be run
in regard with `before`/`after` hooks.

railties is the only consumer of `tsort`.

Author: Earlopain

Gemfile.lock

@@ -104,6 +104,7 @@ PATH
       rackup (>= 1.0.0)
       rake (>= 12.2)
       thor (~> 1.0, >= 1.2.2)
+      tsort (>= 0.2)
       zeitwerk (~> 2.6)
 
 PATH
@@ -681,6 +682,7 @@ GEM
     tomlrb (2.0.3)
     trailblazer-option (0.1.2)
     trilogy (2.9.0)
+    tsort (0.2.0)
     turbo-rails (2.0.11)
       actionpack (>= 6.0.0)
       railties (>= 6.0.0)

railties/railties.gemspec

@@ -45,6 +45,7 @@ Gem::Specification.new do |s|
   s.add_dependency "thor", "~> 1.0", ">= 1.2.2"
   s.add_dependency "zeitwerk", "~> 2.6"
   s.add_dependency "irb", "~> 1.13"
+  s.add_dependency "tsort", ">= 0.2"
 
   s.add_development_dependency "actionview", version
 end