Deprecate the EditPageBeforeEditToolbar hook

This hook has become defunct after the classic edit toolbar was removed.
Its only uses are to disable it, which is pointless as the toolbar
doesn't display when the hook doesn't provide any content.

Bug: T278563
Change-Id: I3285d01715f32a028ea9d5710800c4fd30fe1c59

RELEASE-NOTES-1.36

@@ -729,6 +729,9 @@ because of Phabricator reports.
   ::authorizeMerge instead.
 * User::isValidUserName(), deprecated in 1.35, is hard deprecated.
   Use the UserNameUtils service instead.
+* The EditPageBeforeEditToolbar hook has been deprecated; it has become
+  defunct after the classic edit toolbar was removed. Use one of the many
+  other EditPage hooks instead.
 * …
 
 === Other changes in 1.36 ===

includes/Hook/EditPageBeforeEditToolbarHook.php

@@ -14,6 +14,7 @@ interface EditPageBeforeEditToolbarHook {
 	 * Use this hook to add an edit toolbar above the textarea in the edit form.
 	 *
 	 * @since 1.35
+	 * @deprecated 1.36 Use one of the many other EditPage hooks instead
 	 *
 	 * @param string &$toolbar Toolbar HTML, initially an empty `<div id="toolbar"></div>`
 	 * @return bool|void True or no return value to continue, or false to have

includes/HookContainer/DeprecatedHooks.php

@@ -47,6 +47,7 @@ class DeprecatedHooks {
 		'CanIPUseHTTPS' => [ 'deprecatedVersion' => '1.35' ],
 		'DiffRevisionTools' => [ 'deprecatedVersion => 1.35' ],
 		'DiffViewHeader' => [ 'deprecatedVersion' => '1.35' ],
+		'EditPageBeforeEditToolbar' => [ 'deprecatedVersion' => '1.36' ],
 		'HistoryRevisionTools' => [ 'deprecatedVersion => 1.35' ],
 		'InternalParseBeforeSanitize' => [ 'deprecatedVersion' => '1.35' ],
 		'MagicWordwgVariableIDs' => [ 'deprecatedVersion' => '1.35', 'silent' => true ],