build: bump protobuf from 5.28.2 to 5.28.3 in the grpc-deps group

Bumps the grpc-deps group with 1 update: [protobuf](https://github.com/protocolbuffers/protobuf).


Updates `protobuf` from 5.28.2 to 5.28.3
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v5.28.2...v5.28.3)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: grpc-deps
...

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

pyproject.toml

@@ -56,7 +56,7 @@ tests = [
     "grpcio-health-checking==1.67.0",
     "numpy==2.1.2",
     "Pint==0.24.3",
-    "protobuf==5.28.2",
+    "protobuf==5.28.3",
     "pytest==8.3.3",
     "pytest-cov==5.0.0",
     "pytest-pyvista==0.1.9",
@@ -93,7 +93,7 @@ doc = [
     "numpy==2.1.2",
     "panel==1.5.3",
     "Pint==0.24.3",
-    "protobuf==5.28.2",
+    "protobuf==5.28.3",
     "pyvista[jupyter]==0.44.1",
     "requests==2.32.3",
     "scipy==1.14.1",