Remove MDX Fragment hack (#5716)

* Remove MDX Fragment hack

* Update .changeset/lovely-terms-drive.md

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

Author: bluwy

.changeset/lovely-terms-drive.md

@@ -0,0 +1,5 @@
+---
+'astro': major
+---
+
+Remove MDX Fragment hack. This was used by `@astrojs/mdx` to access the `Fragment` component, but isn't require anymore since `@astrojs/mdx` v0.12.1.

packages/astro/src/core/render/core.ts

@@ -3,7 +3,7 @@ import type { LogOptions } from '../logger/core.js';
 import type { RenderContext } from './context.js';
 import type { Environment } from './environment.js';
 
-import { Fragment, renderPage as runtimeRenderPage } from '../../runtime/server/index.js';
+import { renderPage as runtimeRenderPage } from '../../runtime/server/index.js';
 import { attachToResponse } from '../cookies/index.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
 import { getParams } from '../routing/params.js';
@@ -113,14 +113,6 @@ export async function renderPage(mod: ComponentInstance, ctx: RenderContext, env
 		Object.assign(pageProps, { components: (mod as any).components });
 	}
 
-	// HACK: expose `Fragment` for all MDX components
-	// TODO: Remove in Astro v2 — redundant as of @astrojs/mdx@>0.12.0
-	if (typeof mod.default === 'function' && mod.default.name.startsWith('MDX')) {
-		Object.assign(pageProps, {
-			components: Object.assign((pageProps?.components as any) ?? {}, { Fragment }),
-		});
-	}
-
 	const response = await runtimeRenderPage(
 		result,
 		Component,