[Enhancement] Bump protobuf to 3.20.3

[mys007]

Motivation

There are still many Python packages around which stick with the old 3.20 protobuf version. However, this is typically the very last release of major version 3: 3.20.3. Unfortunately, mmdeploy enforces constraint of 3.20.2, which leads to unnecessary incompatibilities.

Modification

I propose to bump the patch version of protobuf to 3.20.3. This is very likely of no relevance to mmdeploy but makes cohabitation with many other packages possible.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit tests to ensure the correctness.
3. If the modification has a dependency on downstream projects of a newer version, this PR should be tested with all supported versions of downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.

[mys007]

Just bumping this, could "build / build_cuda117" be rerun? It failed without a good reason. Thanks:)