ci: simplify pipelines and setup jest to follow fluent core setup

[Hotell]

• removes redundant docs job from PR pipeline
• migratest to latest https://github.com/nrwl/nx-set-shas
• uses env variables to set NX common CLI args
• uses same jest setup as in core chore: improve jest speed on both local and CI fluentui#32096 ( although there seems to be no perf gains because GHA runs on weak machine )