* [QA][Code Coverage] fixup for auto config handling pr
## Summary
Embed buildkite pipeline definition.
Follow up pr to change cc per auto config handling.
Also, resolves https://github.com/elastic/kibana/issues/132706
Increase worker count for `node scripts/build_kibana_platform_plugins` to 4 workers.
Normalize file names within coverage files such that nyc correctly builds the combined summaries.
_Ci runs this on myriad servers, so the paths are different, which "breaks" nyc's output_
Split the final merge of functional coverage into 2 passes due to [nyc issue](https://github.com/istanbuljs/nyc/issues/1263)
Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>
