investigate protobuf compile issues

[pjfanning]

• example: https://github.com/apache/pekko-connectors/actions/runs/22121965485
• scaladoc build fails due to protobuf build issues
• has been worked around but we may want to report the issue to Scala team

[pjfanning]

It now seems that it is the jar publish that is what fails. I split the nightly job to publish the docs separately from the jars and it is the jar publish that fails. The scaladoc tool is having problems with some genearated Java files for our gRPC based connectors.

[raboof]

hmm indeed:

https://github.com/apache/pekko-connectors/actions/runs/22372384698/job/64754381670

[error] /home/runner/work/pekko-connectors/pekko-connectors/google-cloud-bigquery-storage/target/scala-2.13/pekko-grpc/main/com/google/protobuf/JavaFeaturesProto.java:241:13: value lang is not a member of com.google.protobuf.GeneratedMessage.GeneratedExtension[com.google.protobuf.DescriptorProtos.FeatureSet,com.google.protobuf.JavaFeaturesProto.JavaFeatures]
[error]       @java.lang.Deprecated
[error]             ^

it seems scaladoc incorrectly figures java is of type com.google.protobuf.GeneratedMessage.GeneratedExtension[com.google.protobuf.DescriptorProtos.FeatureSet,com.google.protobuf.JavaFeaturesProto.JavaFeatures]. The file looks OK AFAICS. Should we report this upstream?

JavaFeaturesProto.java

[pjfanning]

@raboof there is also a problem in scalac. I worked around that by setting CompileOrder.JavaThenScala.

I'm not sure if it is worth reporting upstream because it will require a standalone reproduction and it could end up being an sbt issue but is most likely an issue in scala and scala3.

I'm pretty sure #1456 fixes our build but I've thought I was making progress with other PRs too.