Kinda sneaky...since we already mutate the jest portion of the
file system (target/kibana-coverage/jest)
by dumping "jest unit" & "jest integration" coverage
into the same "final" directory...go ahead an make "jest integration"
use the same ran file designator as "jest unit".
This saves me from having to add logic for this later on.
* [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>