add missing SLIM_LCD_MENUS checks

[ellensp]

Description

Since #27393 SLIM_LCD_MENUS is broken.

When SLIM_LCD_MENUS is enabled void _lcd_toggle_bed_leveling() is not defined.
resulting in this error

In file included from Marlin/src/lcd/menu/menu_probe_level.cpp:31:0:
Marlin/src/lcd/menu/menu_probe_level.cpp: In function 'void menu_probe_level()':
Marlin/src/lcd/menu/menu_probe_level.cpp:274:56: error: '_lcd_toggle_bed_leveling' was not declared in this scope
         EDIT_ITEM(bool, MSG_BED_LEVELING, &show_state, _lcd_toggle_bed_leveling);
                                                        ^
Marlin/src/lcd/menu/menu_item.h:290:39: note: in definition of macro '_MENU_INNER_F'

Added missing SLIM_LCD_MENUS checks.

Requirements

#define SLIM_LCD_MENUS
A probe I used #define FIX_MOUNTED_PROBE
A LCD I used REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER
Bed leveling I used AUTO_BED_LEVELING_UBL
and to satify the requirments
#define Z_SAFE_HOMING
#define EEPROM_SETTINGS

Benefits

Builds as expected

Configurations

Configuration.zip

[thinkyhead]

We should be more selective about applying the SLIM_LCD_MENUS option. UBL requires an LCD, so for UBL we can assume the item is meant to appear in this portal menu. Likewise, the LCD_BED_LEVELING option presumes certain items will show up, so we might want to except those items from SLIM_LCD_MENUS too.

The new menu is really a rethink of the UX, and where slimming may need to appear also requires a rethink. I left slimming out of this menu because it is such a granular set of items and it is meant to be the main portal to the probe/leveling options, and related things like G34, M42, G27, tramming, X-twist, backlash, etc., that make use of micro-measurements.