fix(deps): require protobuf >= 3.20.2 (#455)

* chore: exclude requirements.txt file from renovate-bot

Source-Link: https://github.com/googleapis/synthtool/commit/f58d3135a2fab20e225d98741dbc06d57459b816
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:7a40313731a7cb1454eef6b33d3446ebb121836738dc3ab3d2d3ded5268c35b6

* update constraints files

* fix(deps): require protobuf 3.20.2

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <partheniou@google.com>
4 files changed