Problem/Motivation
It has been decided to eventually deprecate Field Layout module from Drupal core. It just hasn't happened yet #3007167: [META] Enable layout builder for form displays, and deprecate field_layout, so it is still listed in Drupal 10.1 under "Core (Experimental)":
Field Layout
Allows users to configure the display and form display by arranging fields in several columns.
Machine name: field_layout
Version: 10.1.0
Requires: Layout Discovery (disabled)
Users who are looking for something like Field Group module for grouping and ordering fields in the form display -- but don't know that Field Layout will probably be removed -- may consider using it for this, since that is what the description says it enables:
Allows users to configure the display and form display by arranging fields in several columns.
Proposed resolution
Inform users via the the module description shown on the module page ("Extend"), that it has been decided to remove the module, and include ID of the relevant issue ^^.