Bump protobuf from 3.20.1 to 4.21.0

Bumps [protobuf]() from 3.20.1 to 4.21.0.

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 defusedxml==0.7.1
-protobuf==3.20.1
+protobuf==4.21.0
 pycryptodomex==3.14.1
 pyogg==0.6.14a.1
 requests==2.27.1