Bump aiohttp from 3.7.4 to 3.8.5 in /grpc_serve

Bumps [aiohttp](https://github.com/aio-libs/aiohttp) from 3.7.4 to 3.8.5.
- [Release notes](https://github.com/aio-libs/aiohttp/releases)
- [Changelog](https://github.com/aio-libs/aiohttp/blob/v3.8.5/CHANGES.rst)
- [Commits](aio-libs/aiohttp@v3.7.4...v3.8.5)

---
updated-dependencies:
- dependency-name: aiohttp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

grpc_serve/requirements-serve.txt

@@ -1,6 +1,6 @@
 numpy==1.21.0
 lightgbm==3.2.1
-aiohttp==3.7.4
+aiohttp==3.8.5
 protobuf==3.10.0
 grpcio==1.24.1
 grpcio-tools==1.24.1