(feat) Refactored all examples to remove references to private keys. Added the use of dotenv to load private keys into environment variables. Removed asyncio package dependency

Author: abel

pyproject.toml

@@ -40,7 +40,7 @@ websockets = "*"
 web3 = "^6.0"
 
 [tool.poetry.group.test.dependencies]
-pytest = "*"
+pytest = "<8"
 pytest-asyncio = "*"
 pytest-grpc = "*"
 requests-mock = "*"