fix(core): do not apply theme-init alias to user component (#5983)

Co-authored-by: sebastienlorber <lorber.sebastien@gmail.com>

website/src/theme/CodeBlock/index.tsx

@@ -0,0 +1,17 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import React from 'react';
+import type {Props} from '@theme/CodeBlock';
+import CodeBlock from '@theme-original/CodeBlock';
+
+// This component does nothing on purpose
+// Dogfood: wrapping a theme component already enhanced by another theme
+// See https://github.com/facebook/docusaurus/pull/5983
+export default function CodeBlockWrapper(props: Props): JSX.Element {
+  return <CodeBlock {...props} />;
+}