drop python 3.7 support

Author: allen-k1m

instrumentation/opentelemetry-instrumentation-asyncio/pyproject.toml

@@ -18,7 +18,6 @@ classifiers = [
   "License :: OSI Approved :: Apache Software License",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3",
-  "Programming Language :: Python :: 3.7",
   "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",