Since v3.83.0, buildkite-agent artifact upload hangs on Windows

Our Windows builds started hanging during `buildkite-agent artifact upload` with the release of `v3.83.0`, and is not resolved with `v3.83.1`. We've implemented a timeout as a workaround.

See here: https://github.com/elastic/elasticsearch/blob/f99321b325e742dee383817afbc4055e7b7eaf6f/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchBuildCompletePlugin.java#L160-L169

- [Last build without hanging](https://buildkite.com/elastic/elasticsearch-periodic-packaging/builds/4015#01926dba-4998-4110-88b5-ecf4273fb1d0/195-1531)
- [First build with hanging](https://buildkite.com/elastic/elasticsearch-periodic-packaging/builds/4019#01926f71-f287-4209-bf64-82d3f2695cf2/197-1526)

Notice the agent versions for the agents that ran those jobs.

Start with the ElasticsearchBuildCompletePlugin.java reference at lines 160-169 and compare the last successful and first hanging Buildkite jobs, including their agent versions. Trace the artifact upload entry point in the agent and reproduce the hang on Windows. Done means artifact upload completes without requiring the timeout workaround for the affected agent versions.

Written by the indexing model from the issue text.