getRuntimeChunk() {
		if (this._runtimeChunk) return this._runtimeChunk;
		for (const parent of this.parentsIterable) {
			if (parent instanceof Entrypoint) return parent.getRuntimeChunk();
		}
		return null;
	}
Fetches the chunk reference containing the webpack bootstrap code
@returns {Chunk | null} returns the runtime chunk or null if there is none