[Bug]: Javadoc generation fails on Java11

[Abacn]

What happened?

During 2.60.0 release, javadoc generation fails on Java11:

https://github.com/apache/beam/actions/runs/11263967402/job/31323007010

/home/runner/work/beam/beam/beam/runners/flink/src/main/java/org/apache/beam/runners/flink/FlinkBatchTranslationContext.java:24: error: package org.apache.beam.runners.flink.translation.utils does not exist
import org.apache.beam.runners.flink.translation.utils.LookupPipelineVisitor;
                                                      ^
100 errors
2 warnings

Using Java8, there is also many "error: package ... does not exist" due to some sources were excluded from doc generation. However it does not fail the task.

Issue Priority

Priority: 2 (default / most bugs should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Infrastructure
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner