Fixes #3420981 Convert FieldType plugin discovery to attributes

Closes #3420981

core/lib/Drupal/Core/Field/Attribute/FieldType.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Core\Field\Attribute;
+
+use Drupal\Component\Plugin\Attribute\Plugin;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Defines a FieldType attribute.
+ *
+ * Additional attribute keys for field types can be defined in
+ * hook_field_info_alter().
+ *
+ * @ingroup field_types
+ */
+#[\Attribute(\Attribute::TARGET_CLASS)]
+class FieldType extends Plugin {
+
+  /**
+   * Constructs a FieldType attribute.
+   *
+   * @param string $id
+   *   The plugin ID.
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup $label
+   *   The human-readable name of the field type.
+   * @param \Drupal\Core\StringTranslation\TranslatableMarkup|array|null $description
+   *   (optional) A short human-readable description for the field type.
+   * @param string $category
+   *   (optional) The category under which the field type should be listed in
+   *   the UI.
+   * @param int $weight
+   *   (optional) The weight of the field type.
+   * @param string|null $default_widget
+   *   (optional) The plugin_id of the default widget for this field type.
+   *   This widget must be available whenever the field type is available (i.e.
+   *   provided by the field type module, or by a module the field type module
+   *   depends on).
+   * @param string|null $default_formatter
+   *   (optional) The plugin_id of the default formatter for this field type.
+   *   This formatter must be available whenever the field type is available
+   *   (i.e. provided by the field type module, or by a module the field type
+   *   module depends on).
+   * @param bool $no_ui
+   *   (optional) A boolean stating that fields of this type cannot be created
+   *   through the UI.
+   * @param string|null $list_class
+   *   (optional) The typed data class used for wrapping multiple data items of
+   *   the type. Must implement the \Drupal\Core\TypedData\ListInterface.
+   * @param int|null $cardinality
+   *   (optional) An integer defining a fixed cardinality for this field type.
+   *   If this value is not set, cardinality can be configured in the field UI.
+   * @param array $constraints
+   *   (optional) An array of validation constraints for this type.
+   * @param array $config_dependencies
+   *   (optional) An array of configuration dependencies.
+   * @param array $column_groups
+   *   (optional) An array of column groups for the field type.
+   * @param array $serialized_property_names
+   *   (optional) An array of property names that should be serialized.
+   * @param string|null $deriver
+   *   (optional) The deriver class for the data type.
+   * @param string|null $module
+   *   The name of the module providing the field type plugin.
+   */
+  public function __construct(
+    public readonly string $id,
+    public readonly TranslatableMarkup $label,
+    public readonly TranslatableMarkup|array|null $description = NULL,
+    public readonly string $category = '',
+    public readonly int $weight = 0,
+    public readonly ?string $default_widget = NULL,
+    public readonly ?string $default_formatter = NULL,
+    public readonly bool $no_ui = FALSE,
+    public readonly ?string $list_class = NULL,
+    public readonly ?int $cardinality = NULL,
+    public readonly array $constraints = [],
+    public readonly array $config_dependencies = [],
+    public readonly array $column_groups = [],
+    public readonly array $serialized_property_names = [],
+    public readonly ?string $deriver = NULL,
+    public readonly ?string $module = NULL,
+  ) {
+  }
+
+}