📝 Provide detailed reproduction steps (if any)

1. Set tokenUrl to a function call that throws an error:

cloudServices: {
		tokenUrl: async () => {
			const response = {status: 404}
		   
			if (response.status < 200 || response.status > 299) {
			throw new Error('Cannot download new token.');
			}
		   
			if (typeof response.data !== 'string') {
			throw new Error('Unable to parse token.');
			}
		   
			return response.data;
		   },

✔️ Expected result

• after editor crashes, the getToken interval call should be cleared

❌ Actual result

• getToken interval call is being executed indefinitely

📃 Other details

• Browser: n/a
• OS: n/a
• First affected CKEditor version: n/a
• Installed CKEditor plugins: …

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