input: Write a python function to fetch JSON data from a given URL using aiohttp and asyncio.
  assert asyncio.run(fetch_data('http://example.com/data1.json')) == {'key1': 'value1'}
  assert asyncio.run(fetch_data('http://example.com/data2.json')) == {'key2': 'value2'}
  assert asyncio.run(fetch_data('http://example.com/data3.json')) == {'key3': 'value3'}
output: import aiohttp
  import asyncio
  
  async def fetch_data(url):
      async with aiohttp.ClientSession() as session:
          async with session.get(url) as response:
              return await response.json()