Deprecate OCP\Util::connectHook and emitHook

[MorrisJobke]

typed events and the \OCP\EventDispatcher\IEventDispatcher service should be used.

Ref #14552

• add to Critical changes for developers & admins for Nextcloud 21 #23210

[faily-bot]

🤖 beep boop beep 🤖

Here are the logs for the failed build:

Status of 34716: failure

acceptance-header

• tests/acceptance/features/header.feature:33

Show full log

 Scenario: users from other groups are not seen in the contacts menu when autocompletion is restricted within the same group # /drone/src/tests/acceptance/features/header.feature:33
Given I am logged in as the admin # LoginPageContext::iAmLoggedInAsTheAdmin()
And I visit the settings page # SettingsMenuContext::iVisitTheSettingsPage()
And I open the "Sharing" section of the "Administration" group # AppNavigationContext::iOpenTheSectionOf()
And I enable restricting username autocompletion to groups # SettingsContext::iEnableRestrictingUsernameAutocompletionToGroups()
And I see that username autocompletion is restricted to groups # SettingsContext::iSeeThatUsernameAutocompletionIsRestrictedToGroups()
When I open the Contacts menu # ContactsMenuContext::iOpenTheContactsMenu()
Then I see that the Contacts menu is shown # ContactsMenuContext::iSeeThatTheContactsMenuIsShown()
And I see that the contact "user0" in the Contacts menu is not shown # ContactsMenuContext::iSeeThatTheContactInTheContactsMenuIsNotShown()
Failed asserting that true is false.
And I see that the contact "admin" in the Contacts menu is not shown # ContactsMenuContext::iSeeThatTheContactInTheContactsMenuIsNotShown()