diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index e2e72fb367482..d5b77a737836c 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -42,7 +42,6 @@ includes:
 	- tests/phpstan/baselines/empty.offset.neon
 	- tests/phpstan/baselines/empty.property.neon
 	- tests/phpstan/baselines/empty.variable.neon
-	- tests/phpstan/baselines/encapsedStringPart.nonString.neon
 	- tests/phpstan/baselines/foreach.nonIterable.neon
 	- tests/phpstan/baselines/function.alreadyNarrowedType.neon
 	- tests/phpstan/baselines/function.impossibleType.neon
diff --git a/src/wp-admin/includes/media.php b/src/wp-admin/includes/media.php
index 6c50a1daba4fd..c17e68e34c363 100644
--- a/src/wp-admin/includes/media.php
+++ b/src/wp-admin/includes/media.php
@@ -1398,7 +1398,10 @@ function image_media_send_to_editor( $html, $attachment_id, $attachment ) {
  *
  * @param WP_Post $post
  * @param array   $errors
- * @return array<string, array<string, mixed>> The attachment fields.
+ * @return array<string, string|array<string, mixed>> The attachment fields, keyed by field name. Each value is a field
+ *                                                    definition array, except for underscore-prefixed keys such as
+ *                                                    `_final`, which the `attachment_fields_to_edit` filter may set to
+ *                                                    raw HTML.
  */
 function get_attachment_fields_to_edit( $post, $errors = null ) {
 	if ( is_int( $post ) ) {
diff --git a/tests/phpstan/baselines/encapsedStringPart.nonString.neon b/tests/phpstan/baselines/encapsedStringPart.nonString.neon
deleted file mode 100644
index 707a2192a4c8a..0000000000000
--- a/tests/phpstan/baselines/encapsedStringPart.nonString.neon
+++ /dev/null
@@ -1,25 +0,0 @@
-# PHPStan baseline for the `encapsedStringPart.nonString` errors in WordPress core.
-#
-# https://phpstan.org/error-identifiers/encapsedStringPart.nonString
-#
-# Each entry is scoped to a single file and carries an exact occurrence count,
-# so that a new instance is reported as a new error rather than being absorbed
-# silently. Fixing an occurrence therefore means decrementing or removing its
-# entry here as part of the same change.
-#
-# The goal is to empty this file and delete it, along with the `includes` entry
-# for it in phpstan.neon.dist.
-#
-# Generated by `composer phpstan:baselines`. Do not edit by hand; regenerate with
-#
-#     composer phpstan:baselines -- --identifier=encapsedStringPart.nonString
-#
-# which reruns the analysis with this file suppressed so the errors surface again.
-
-parameters:
-	ignoreErrors:
-		-
-			message: '#^Part \$form_fields\[''_final''\] \(non\-empty\-array\<string, mixed\>\) of encapsed string cannot be cast to string\.$#'
-			identifier: encapsedStringPart.nonString
-			count: 1
-			path: ../../../src/wp-admin/includes/media.php