Add typehints to hook definitions

I think it's a good idea. I've been using type hints in my hook implementations, even if the hook itself doesn't specify types. I'm trying to use stricter coding standards.

This is a duplicate as noted in the other issue.

Re-opening and moving to a child of 📌 [META] Add return types to hook implementations Active because there are a lot of hook definitions (in .api.php files) that were not updated in some of the wildcard issues, like all info hooks. I think we can use this to identify and fix any leftovers.

Postponing on 📌 Add void return to @ingroup entity_crud hook implementations Active and 📌 Add return type to remaining hook implementations Active . Added steps to reproduce. Added a draft MR with all the alter hooks updated.

No longer postponed. Just realised that the IS is talking about both params and return types. I think initially we should limit this to return types and split off params to another ticket.

$ grep -rn --include="*.api.php" -E 'function hook_.*\(.*\) \{' core
core/lib/Drupal/Core/Extension/module.api.php:782:function hook_update_N(&$sandbox) {
core/lib/Drupal/Core/Extension/module.api.php:784:  // function hook_update_N() {
core/lib/Drupal/Core/Extension/module.api.php:892:function hook_post_update_NAME(&$sandbox) {
core/lib/Drupal/Core/Extension/module.api.php:1303:function hook_update_requirements() {
core/modules/shortcut/shortcut.api.php:40:function hook_shortcut_default_set(AccountInterface $account) {
core/modules/jsonapi/jsonapi.api.php:276:function hook_jsonapi_entity_filter_access(EntityTypeInterface $entity_type, AccountInterface $account) {
core/modules/field/field.api.php:394:function hook_field_info_max_weight($entity_type, $bundle, $context, $context_mode) {