fix: void elements (#10493)

* Fix void elements

HTML is not XML. It doesn't have self-closing tags, it has void element tags that don't need closing slashes.

Now generated void elements (e.g. link with path to style file) do not pass validation, which can be easily fixed by simply removing two characters.

* Add changeset

* Apply suggestions from code review

---------

Co-authored-by: Arsh <[email protected]>

.changeset/thick-games-thank.md

@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+`<link>` tags created by astro for optimized stylesheets now do not include the closing forward slash. This slash is optional for void elements such as link, but made some html validation fail.

packages/astro/src/runtime/server/render/util.ts

@@ -144,7 +144,7 @@ export function renderElement(
 		}
 	}
 	if ((children == null || children == '') && voidElementNames.test(name)) {
-		return `<${name}${internalSpreadAttributes(props, shouldEscape)} />`;
+		return `<${name}${internalSpreadAttributes(props, shouldEscape)}>`;
 	}
 	return `<${name}${internalSpreadAttributes(props, shouldEscape)}>${children}</${name}>`;
 }