Apply consistent symbol/string attribute transformation for Hash values

Symbol attribute keys are dasherized before rendering, whereas string
keys are passed through verbatim.

However if the value is a Hash, the dasherize transform will not be
applied to the key even if it is a symbol. This change makes it so the
dasherization is applied even in this case.

```rb
a(data_turbo: { method: "post", confirm: "Are you sure?" })
```

Should render

```html
<a data-turbo-method="post" data-turbo-confirm="Are you sure?"></a>
```

lib/phlex/sgml.rb

@@ -409,8 +409,8 @@ def __build_attributes__(attributes, buffer:)
 					__build_attributes__(
 						v.transform_keys { |subkey|
 							case subkey
-								when Symbol then"#{k}-#{subkey.name.tr('_', '-')}"
-								else "#{k}-#{subkey}"
+								when Symbol then"#{name}-#{subkey.name.tr('_', '-')}"
+								else "#{name}-#{subkey}"
 							end
 						}, buffer: buffer
 					)

test/phlex/view/tags.rb

@@ -43,6 +43,30 @@
 				expect(output).to be == %(<#{tag} class="class" id="id" disabled>content</#{tag}>)
 			end
 		end
+
+		with "<#{tag}> with string attribute keys" do
+			view do
+				define_method :template do
+					send(method_name, "attribute_with_underscore" => true) { "content" }
+				end
+			end
+
+			it "produces the correct output" do
+				expect(output).to be == %(<#{tag} attribute_with_underscore>content</#{tag}>)
+			end
+		end
+
+		with "<#{tag}> with hash attribute values" do
+			view do
+				define_method :template do
+					send(method_name, aria: { hidden: true }, data_turbo: { frame: "_top" }) { "content" }
+				end
+			end
+
+			it "produces the correct output" do
+				expect(output).to be == %(<#{tag} aria-hidden data-turbo-frame="_top">content</#{tag}>)
+			end
+		end
 	end
 
 	Phlex::HTML::VoidElements.registered_elements.each do |method_name, tag|
@@ -73,5 +97,29 @@
 				expect(output).to be == %(<#{tag} class="class" id="id" disabled>)
 			end
 		end
+
+		with "<#{tag}> with string attribute keys" do
+			view do
+				define_method :template do
+					send(method_name, "attribute_with_underscore" => true)
+				end
+			end
+
+			it "produces the correct output" do
+				expect(output).to be == %(<#{tag} attribute_with_underscore>)
+			end
+		end
+
+		with "<#{tag}> with hash attribute values" do
+			view do
+				define_method :template do
+					send(method_name, aria: { hidden: true }, data_turbo: { frame: "_top" })
+				end
+			end
+
+			it "produces the correct output" do
+				expect(output).to be == %(<#{tag} aria-hidden data-turbo-frame="_top">)
+			end
+		end
 	end
 end