Issue #3384347: Remove entity id mapping config

config/schema/search_api_meilisearch.schema.yml

-search_api_meilisearch.settings:
-  type: config_object
-  label: 'Search API MeiliSearch configuration'
-  mapping:
-    meilisearch_id_mappings:
-      type: sequence
-      label: "Mapping of the drupal items id's to MeiliSearch ids"
-      sequence:
-        type: sequence
-        label: 'Index id'
-        sequence:
-          type: string
-          label: 'Entity id'