Test structure was stale. Update to conform to recent changes in main...

Specifically, PR 3840 updated bundler and required changes to test
setup. #3840

Author: jconley88

test/setup_bundler_test.rb

@@ -317,24 +317,21 @@ def test_creates_composed_bundle_with_specified_branch
   end
 
   def test_creates_composed_bundle_with_specified_path
-    Dir.mktmpdir do |dir|
+    in_temp_dir do |dir|
       local_path = File.join(dir, "local-ruby-lsp")
       FileUtils.mkdir_p(File.join(local_path, "lib"))
-      
-      Dir.chdir(dir) do
-        bundle_gemfile = Pathname.new(".ruby-lsp").expand_path(Dir.pwd) + "Gemfile"
-        Bundler.with_unbundled_env do
-          stub_bundle_with_env(bundle_env(dir, bundle_gemfile.to_s))
-          run_script(File.realpath(dir), lsp_path: local_path)
-        end
-  
-        assert_path_exists(".ruby-lsp")
-        assert_path_exists(".ruby-lsp/Gemfile")
-        assert_match(%r{ruby-lsp.*path: "#{Regexp.escape(local_path)}"}, File.read(".ruby-lsp/Gemfile"))
-        assert_match("debug", File.read(".ruby-lsp/Gemfile"))
+
+      Bundler.with_unbundled_env do
+        stub_bundle_with_env(bundle_env(dir, ".ruby-lsp/Gemfile"))
+        run_script(File.realpath(dir), lsp_path: local_path)
       end
+
+      assert_path_exists(".ruby-lsp")
+      assert_path_exists(".ruby-lsp/Gemfile")
+      assert_match(%r{ruby-lsp.*path: "#{Regexp.escape(local_path)}"}, File.read(".ruby-lsp/Gemfile"))
+      assert_match("debug", File.read(".ruby-lsp/Gemfile"))
     end
-  end  
+  end
 
 
   def test_returns_bundle_app_config_if_there_is_local_config