protobuf v4 (4.21.0) compatibility

[gitpushdashf]

Hi DataDog,

Would it be possible to add protobuf v4 support?

https://github.com/DataDog/dd-trace-py/blob/1.x/setup.py#L244

https://github.com/protocolbuffers/protobuf/releases/tag/v21.0

https://pypi.org/project/protobuf/

Thank you!

[brettlangdon]

hey @gitpushdashf thanks for opening this issue... coming soon!!

#3767

[gitpushdashf]

Wow, great. Thank you!