botocore: drop hardcoded aiohttp dependency

There was an incompatibility with latest releases of vcr.py and aiohttp
so that aiobotocore tests would have failed. Latest vcrpy fixed that so
we can remove the aiohttp pinned version.

Author: xrmx

instrumentation/opentelemetry-instrumentation-botocore/test-requirements-2.txt

@@ -3,7 +3,6 @@ aws-xray-sdk==2.12.1
 boto3==1.29.4
 botocore==1.32.4
 aiobotocore==2.8.0
-aiohttp==3.9.1 #TODO: https://github.com/open-telemetry/opentelemetry-python-contrib/issues/4645 - fix issue with aiohttp in a better way.
 certifi==2024.7.4
 cffi==1.17.0
 charset-normalizer==3.3.2