Bump Google.Protobuf from 3.26.1 to 3.28.3 in /src/Miningcore

Bumps [Google.Protobuf](https://github.com/protocolbuffers/protobuf) from 3.26.1 to 3.28.3.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v3.26.1...v3.28.3)

---
updated-dependencies:
- dependency-name: Google.Protobuf
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Miningcore/Miningcore.csproj

@@ -85,7 +85,7 @@
         <PackageReference Include="System.Diagnostics.Process" Version="4.3.0" />
         <PackageReference Include="System.Reactive" Version="6.0.0" />
         <PackageReference Include="Grpc.AspNetCore" Version="2.57.0" />
-        <PackageReference Include="Google.Protobuf" Version="3.26.1" />
+        <PackageReference Include="Google.Protobuf" Version="3.28.3" />
         <PackageReference Include="Grpc.Net.Client" Version="2.62.0" />
         <PackageReference Include="Grpc.Tools" Version="2.62.0">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>