Remove Mission Control and Launchpad from Keychron boards

[adophoxia]

Description

Since the keycodes, MISSION_CONTROL and LAUNCHPAD are now moved into core over in qmk/qmk_firmware, there's no need to keep them inside the v3 JSONs.

QMK Pull Request

• Move KC_MISSION_CONTROL/KC_LAUNCHPAD keycodes to core qmk/qmk_firmware#19884

Checklist

• The VIA support for this keyboard is MERGED in QMK master already (MANDATORY)
• The VIA definition follows the guide here: https://caniusevia.com/docs/layouts
• I have a V3 JSON version for this keyboard definition.(MANDATORY)
• I have tested this keyboard definition using VIA's "Design" tab.
• I have tested this keyboard definition with firmware on a device.
• I have assigned alpha keys and modifier keys with the correct colors.
• The Vendor ID is not 0xFEED