Bump Google.Protobuf from 3.25.1 to 3.26.0 in /dotnet-etcd

Bumps [Google.Protobuf](https://github.com/protocolbuffers/protobuf) from 3.25.1 to 3.26.0.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v3.25.1...v3.26.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

dotnet-etcd/dotnet-etcd.csproj

@@ -58,7 +58,7 @@ Advanced uses take advantage of the consistency guarantees to implement database
 
   <ItemGroup>
     <PackageReference Include="Google.Api.CommonProtos" Version="2.13.0" />
-    <PackageReference Include="Google.Protobuf" Version="3.25.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.26.0" />
     <PackageReference Include="Grpc.Net.Client" Version="2.60.0" />
     <PackageReference Include="Grpc.Tools" Version="2.60.0">
       <PrivateAssets>all</PrivateAssets>