fix: Limit number of labels added to 100 (#497)

* push to excess labels to avoid reaching the limit

* build dist

* never set more than 100 labels

* use splice instead of set

* ignore IDE folders

* install @octokit/plugin-retry

* always setLabels

* fix indentations

* fix specs

* add spec for excess labels

* prettier

* licensed cache

* revert to !!core.getInput('sync-labels')

* better warning for exceeded labels

* keep manually-added labels

* nest the dedupe logic

* rename `removeLabel` to `removeLabelFromList` to avoid confusion

* use Sets, and issue a call only if labels have actually changed

* remove IDE config folders from gitignore

* remove obsolete duplucation check

---------

Co-authored-by: Mark Massoud <mark@unrealcloud.io>

__mocks__/@actions/github.ts

@@ -13,8 +13,7 @@ export const context = {
 const mockApi = {
   rest: {
     issues: {
-      addLabels: jest.fn(),
-      removeLabel: jest.fn()
+      setLabels: jest.fn()
     },
     pulls: {
       get: jest.fn().mockResolvedValue({}),