Rely on existing RDoc fixture test

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 93ffdf64-9ffd-47b4-b3d4-96dda4ae722d

Author: joelhawksley

test/coverage_test.rb

@@ -94,10 +94,6 @@ def test_try_require_returns_false_for_missing_gem
     refute md.send(:try_require, "github_markup_definitely_not_a_real_gem_#{Time.now.to_i}")
   end
 
-  def test_rdoc_renders_with_installed_version
-    assert_includes GitHub::Markup::RDoc.new.render("README.rdoc", "*bold*"), "<strong>bold</strong>"
-  end
-
   # --- implementation.rb default render and Linguist-less match? ---------
 
   def test_base_implementation_render_raises_not_implemented_error

test/markup_test.rb

@@ -107,23 +107,6 @@ def test_rendering_by_symbol
     assert_match result, GitHub::Markup.render_s(GitHub::Markups::MARKUP_ASCIIDOC, markup).split.join
   end
 
-  def test_rdoc_rendering_by_filename_and_symbol
-    source = "= Title\n\nA *bold* paragraph.\n\n* One\n* Two\n"
-    results = [
-      GitHub::Markup.render("README.rdoc", source),
-      GitHub::Markup.render_s(GitHub::Markups::MARKUP_RDOC, source),
-    ]
-
-    results.each do |result|
-      document = Nokogiri::HTML.fragment(result)
-      document.css("h1 > span").remove
-      assert_equal "Title", document.at_css("h1").text
-      assert_equal "bold", document.at_css("p strong").text
-      assert_equal ["One", "Two"], document.css("ul li").map { |item| item.text.strip }
-    end
-    assert_equal results.first, results.last
-  end
-
   def test_raises_error_if_command_exits_non_zero
     GitHub::Markup.command(:doesntmatter, 'test/fixtures/fail.sh', /fail/, ['Java'], 'fail')
     assert GitHub::Markup.can_render?('README.java', 'stop swallowing errors')