fix wrapping classes when targeting ESNext

[clydin]

This conforms to the behavior present in the class fields transformer:

TypeScript/src/compiler/transformers/classFields.ts

Lines 70 to 75 in c1f676d

	function transformSourceFile(node: SourceFile) {
	const options = context.getCompilerOptions();
	if (node.isDeclarationFile
	|| options.useDefineForClassFields && options.target === ScriptTarget.ESNext) {
	return node;
	}

Fixes #38528