Fix Ruby 4.0 warning: default before_template/after_template now accept a block

The call site in SGML#call passes a block to both methods via `&block`,
but the default no-op implementations had no block parameter. Ruby 4.0
warns about this ("block passed to method may be ignored"). Adding `(&)`
to both signatures silently accepts the block without using it.

Author: ErnaneJ

lib/phlex/sgml.rb

@@ -326,11 +326,11 @@ def json_escape(string)
 		nil
 	end
 
-	private def before_template
+	private def before_template(&)
 		nil
 	end
 
-	private def after_template
+	private def after_template(&)
 		nil
 	end
 

quickdraw/sgml/callbacks.test.rb

@@ -30,4 +30,9 @@ def view_template
 	test "callbacks are called in the correct order" do
 		assert_equal Example.call, "<i>1</i><i>2</i><i>3</i><i>4</i><i>5</i><i>6</i><i>7</i>"
 	end
+
+	test "default before_template and after_template accept a block" do
+		klass = Class.new(Phlex::HTML) { def view_template = span { "hello" } }
+		assert_equal klass.call { "ignored" }, "<span>hello</span>"
+	end
 end