Prevent possible warning in `COTMigrationUtil::get_post_or_object_meta()` (#37026)

plugins/woocommerce/changelog/fix-35543

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Prevent possible warning arising from use of woocommerce_wp_* family of functions.

plugins/woocommerce/src/Internal/Utilities/COTMigrationUtil.php

@@ -96,7 +96,7 @@ class COTMigrationUtil {
 			}
 			return $data->get_meta( $key, $single );
 		} else {
-			return get_post_meta( $post->ID, $key, $single );
+			return isset( $post->ID ) ? get_post_meta( $post->ID, $key, $single ) : false;
 		}
 	}