chore: add strict types in IAddressBook::getKey

Signed-off-by: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>

apps/dav/lib/CardDAV/AddressBookImpl.php

@@ -41,9 +41,10 @@ class AddressBookImpl implements IAddressBookEnabled, ICreateContactFromString {
 	/**
 	 * @return string defining the technical unique key
 	 * @since 5.0.0
+	 * @since 35.0.0 Typed return type
 	 */
 	#[\Override]
-	public function getKey() {
+	public function getKey(): string {
 		return (string)$this->addressBookInfo['id'];
 	}
 

lib/public/IAddressBook.php

@@ -18,8 +18,9 @@ namespace OCP {
 		/**
 		 * @return string defining the technical unique key
 		 * @since 5.0.0
+		 * @since 35.0.0 Typed return type
 		 */
-		public function getKey();
+		public function getKey(): string;
 
 		/**
 		 * @return string defining the unique uri