[polari] (19 commits) ...ci: Allow gradual switch to new style

[Florian Müllner <fmuellner src gnome org>]

Summary of changes:

  50658e7... lint: Import eslint rules from gjs (*)
  030b3d2... lint: Tweak the whitelist of globals (*)
  4448897... lint: Require spaces inside braces in object literals (*)
  f5cef23... lint: Enforce arrow notation (*)
  a8e130c... lint: Allow multiple spaces before key values (*)
  7e63efa... lint: Allow single-line braces (*)
  3b4c846... lint: Tweak indenting rule (*)
  6868eca... lint: Don't require indent for GObject.registerClass() (*)
  886f9ae... lint: Add "legacy" configuration (*)
  198b468... lint: Allow marking variables/arguments as unused (*)
  628fd7c... cleanup: Remove some unhelpful unused arguments (*)
  ace718c... cleanup: Mark unused arguments as unused (*)
  efab270... cleanup: Remove some unhelpful unused variables in destruct (*)
  e5a9f74... cleanup: Mark unused (but useful) variables as ignored (*)
  08d8a45... cleanup: Mark globals used from other modules as exported (*)
  a6c07b0... cleanup: Mark non-exported classes as const (*)
  7835847... style: Disable a couple of indent warnings (*)
  47630ff... ci: Add "source_check" stage (*)
  518f34e... ci: Allow gradual switch to new style (*)

(*) This commit already existed in another branch; no separate mail sent