* Reverts the introduction of the lint-staged step for Prettier
* Disables the GH Action for Stylelint

This fixes an issue where non-migrated components were not building
their `vars.css` files correctly. The files were created, but were empty.

To fix, this:

* Restores postcss-dropunusedvars & post-cssdropdupedvars
  and renames them as `legacy-*` prefixed plugins
* Updates component-builder to point to the new legacy plugins
* Restores `vars.js` to its older state

* Updates the GH Actions workflow to use very specific
  commands for each step that we want to invoke. This
  provides clarity as to what is happening in CI.
* Additionally, these specific commands bypass Nx,
  which was not caching the component build step and
  was running multiple times, which caused broken asset
  paths in the docs site.

 - @spectrum-css/accordion@3.0.48
 - @spectrum-css/actionbar@6.0.45
 - @spectrum-css/actionbutton@4.0.3
 - @spectrum-css/actiongroup@3.0.50
 - @spectrum-css/actionmenu@4.0.38
 - @spectrum-css/alertbanner@1.1.6
 - @spectrum-css/asset@3.0.44
 - @spectrum-css/assetcard@1.1.41
 - @spectrum-css/assetlist@3.0.61
 - @spectrum-css/avatar@6.0.34
 - @spectrum-css/badge@3.0.36
 - @spectrum-css/breadcrumb@7.0.37
 - @spectrum-css/button@10.1.4
 - @spectrum-css/buttongroup@6.0.51
 - @spectrum-css/calendar@3.1.24
 - @spectrum-css/card@5.0.39
 - @spectrum-css/checkbox@6.1.2
 - @spectrum-css/clearbutton@1.2.34
 - @spectrum-css/closebutton@3.1.4
 - @spectrum-css/coachmark@5.0.48
 - @spectrum-css/colorarea@4.0.20
 - @spectrum-css/colorhandle@5.0.8
 - @spectrum-css/colorloupe@4.0.8
 - @spectrum-css/colorslider@3.0.16
 - @spectrum-css/colorwheel@3.0.20
 - @spectrum-css/combobox@2.0.15
 - @spectrum-css/commons@7.0.8
 - @spectrum-css/contextualhelp@2.0.14
 - @spectrum-css/cyclebutton@3.0.63
 - @spectrum-css/datepicker@1.0.28
 - @spectrum-css/dial@1.0.47
 - @spectrum-css/dialog@6.0.55
 - @spectrum-css/divider@2.1.6
 - @spectrum-css/dropindicator@3.0.47
 - @spectrum-css/dropzone@5.0.3
 - @spectrum-css/expressvars@3.0.8
 - @spectrum-css/fieldgroup@4.0.51
 - @spectrum-css/fieldlabel@7.0.9
 - @spectrum-css/floatingactionbutton@1.0.9
 - @spectrum-css/helptext@4.0.36
 - @spectrum-css/icon@3.0.47
 - @spectrum-css/illustratedmessage@6.0.3
 - @spectrum-css/infieldbutton@2.0.24
 - @spectrum-css/inlinealert@7.0.27
 - @spectrum-css/link@4.0.47
 - @spectrum-css/logicbutton@1.2.33
 - @spectrum-css/menu@4.0.41
 - @spectrum-css/miller@3.0.61
 - @spectrum-css/modal@3.0.45
 - @spectrum-css/overlay@3.0.9
 - @spectrum-css/page@5.0.31
 - @spectrum-css/pagination@6.0.26
 - @spectrum-css/picker@4.0.14
 - @spectrum-css/pickerbutton@3.0.26
 - @spectrum-css/popover@6.0.53
 - @spectrum-css/progressbar@3.0.47
 - @spectrum-css/progresscircle@2.0.47
 - @spectrum-css/quickaction@3.0.63
 - @spectrum-css/radio@7.0.36
 - @spectrum-css/rating@4.0.7
 - @spectrum-css/search@6.0.1
 - @spectrum-css/searchwithin@4.0.29
 - @spectrum-css/sidenav@3.0.48
 - @spectrum-css/site@3.0.21
 - @spectrum-css/slider@4.0.9
 - @spectrum-css/splitbutton@5.0.50
 - @spectrum-css/splitview@3.0.44
 - @spectrum-css/statuslight@6.0.34
 - @spectrum-css/steplist@3.0.60
 - @spectrum-css/stepper@4.0.37
 - @spectrum-css/swatch@4.0.24
 - @spectrum-css/swatchgroup@2.0.48
 - @spectrum-css/switch@3.1.2
 - @spectrum-css/table@4.0.55
 - @spectrum-css/tabs@3.2.59
 - @spectrum-css/tag@5.0.36
 - @spectrum-css/taggroup@3.3.49
 - @spectrum-css/textfield@6.0.1
 - @spectrum-css/thumbnail@3.0.11
 - @spectrum-css/toast@9.0.36
 - @spectrum-css/tooltip@5.0.36
 - @spectrum-css/tray@2.0.50
 - @spectrum-css/treeview@7.0.5
 - @spectrum-css/typography@5.0.22
 - @spectrum-css/underlay@2.0.52
 - @spectrum-css/vars@9.0.8
 - @spectrum-css/well@3.0.44
 - @spectrum-css/component-builder@4.0.12
 - @spectrum-css/preview@3.0.26