Allow the node search to limit the searchable node bundles

Reviewed and seems to be working fine, good job and absolutely a needed change!

Just a small nitpick, you left a typo in a comment :P
// Turn the filters intp query conditions. This assumes that everything in

After that this is RTBC in my opinion.

Ummmmm.... Why was this not put into the Search module component? I know it's technically in node.module but traditionally, anything about Search has been part of search.module component.

Can the search module maintainers have a moment to review this?

Also this is a duplicate of #111744: Add configuration to exclude node types from search indexing which has been open for YEARS.

1. There is no hook_update_N() for the new configuration. Doesn't there need to be?

2. +++ b/core/lib/Drupal/Core/Entity/EntityTypeBundleInfo.php
   @@ -24,7 +24,9 @@ class EntityTypeBundleInfo implements EntityTypeBundleInfoInterface {
   -   * @var array
   +   * @var array[]
   +   *   Keys are entity types, and values are arrays of bundle information, keyed
   +   *   by bundle name.
       */
   

   This type of change is out of scope for the stated issue. Please move to a separate issue.

3. +++ b/core/lib/Drupal/Core/Entity/EntityTypeBundleInfoInterface.php
   @@ -15,8 +15,9 @@
   -   * @return array
   -   *   An array of all bundle information.
   +   * @return array[]
   +   *   Keys are entity types, and values are arrays of bundle information, keyed
   +   *   by bundle name.
   

   Out of scope.

4. +++ b/core/lib/Drupal/Core/Entity/EntityTypeBundleInfoInterface.php
   @@ -26,8 +27,8 @@ public function getAllBundleInfo();
   -   * @return array
   -   *   Returns the bundle information for the specified entity type.
   +   * @return array[]
   +   *   Bundle information, keyed by bundle name.
   

   Out of scope.

5. +++ b/core/modules/node/config/schema/node.schema.yml
   @@ -45,6 +45,12 @@ search.plugin.node_search:
   +    restricted_searchable_node_bundles:
   

   Why use such a long complicated name for this config?

6. +++ b/core/modules/node/src/Plugin/Search/NodeSearch.php
   @@ -255,21 +257,27 @@ protected function findResults() {
   +    if (!array_key_exists('type', $filters) && $this->configuration['restricted_searchable_node_bundles'] !== []) {
   

   I don't think checking that the configuration == [] is a good way to check -- use the PHP empty() function instead?

7. +++ b/core/modules/node/src/Plugin/Search/NodeSearch.php
   @@ -255,21 +257,27 @@ protected function findResults() {
   +    if (!array_key_exists('type', $filters) && $this->configuration['restricted_searchable_node_bundles'] !== []) {
   +      $filters['type'] = $this->configuration['restricted_searchable_node_bundles'];
   +    }
   

   It seems like we'd need to somehow merge the filters together to enforce this right. And what if someone manually put ?type='article' into the search URL, even though that wasn't allowed as a searchable node bundle? I think it would allow them to search for content that shouldn't be searchable. This needs testing and I think it's wrong.

8. +++ b/core/modules/node/src/Plugin/Search/NodeSearch.php
   @@ -807,6 +825,52 @@ public function submitConfigurationForm(array &$form, FormStateInterface $form_s
   +   * Gets the restricted node bundles.
   

   This is a setter, not a getter.

Anyway I would rather this got marked as a duplicate of #111744: Add configuration to exclude node types from search indexing, since it has a 9 year history and many followers. I'll let you move this patch over there first...

I also want to point out that if you really want to exclude node types from searches, the best way to do it is not to index them in the first place, rather than to index them and then use a filter on the search.