Remove use of ruby taint API for ruby 3.2 compatibility

lib/liquid/standardfilters.rb

@@ -39,7 +39,7 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input.to_s).untaint unless input.nil?
+      CGI.escapeHTML(input.to_s) unless input.nil?
     end
     alias_method :h, :escape
 

lib/liquid/template.rb

@@ -63,10 +63,7 @@ module Liquid
       # :strict will enforce correct syntax.
       attr_writer :error_mode
 
-      # Sets how strict the taint checker should be.
-      # :lax is the default, and ignores the taint flag completely
-      # :warn adds a warning, but does not interrupt the rendering
-      # :error raises an error when tainted output is used
+      # Deprecated. No longer used. Removed in version 5
       attr_writer :taint_mode
 
       attr_accessor :default_exception_renderer
@@ -94,6 +91,7 @@ module Liquid
         @error_mode ||= :lax
       end
 
+      # Deprecated. Removed in version 5
       def taint_mode
         @taint_mode ||= :lax
       end

lib/liquid/variable.rb

@@ -84,11 +84,7 @@ module Liquid
         context.invoke(filter_name, output, *filter_args)
       end
 
-      obj = context.apply_global_filter(obj)
-
-      taint_check(context, obj)
-
-      obj
+      context.apply_global_filter(obj)
     end
 
     private
@@ -120,25 +116,6 @@ module Liquid
       parsed_args
     end
 
-    def taint_check(context, obj)
-      return unless obj.tainted?
-      return if Template.taint_mode == :lax
-
-      @markup =~ QuotedFragment
-      name = Regexp.last_match(0)
-
-      error = TaintedError.new("variable '#{name}' is tainted and was not escaped")
-      error.line_number = line_number
-      error.template_name = context.template_name
-
-      case Template.taint_mode
-      when :warn
-        context.warnings << error
-      when :error
-        raise error
-      end
-    end
-
     class ParseTreeVisitor < Liquid::ParseTreeVisitor
       def children
         [@node.name] + @node.filters.flatten