docs: remove fga_client.close() from README (#191) (#239)

Co-authored-by: Anurag Bandyopadhyay <angbpy@gmail.com>

Author: JsMelix

README.md

@@ -145,7 +145,6 @@ async def main():
     # Enter a context with an instance of the OpenFgaClient
     async with OpenFgaClient(configuration) as fga_client:
         api_response = await fga_client.read_authorization_models()
-        await fga_client.close()
         return api_response
 ```
 
@@ -171,7 +170,6 @@ async def main():
     # Enter a context with an instance of the OpenFgaClient
     async with OpenFgaClient(configuration) as fga_client:
         api_response = await fga_client.read_authorization_models()
-        await fga_client.close()
         return api_response
 ```
 
@@ -200,7 +198,6 @@ async def main():
     # Enter a context with an instance of the OpenFgaClient
     async with OpenFgaClient(configuration) as fga_client:
         api_response = await fga_client.read_authorization_models()
-        await fga_client.close()
         return api_response
 ```