FIX CONFIG: Adding USE_FLASH as a permanent fixture for those targets with flash

[blckmn]

Removing the option for cloud build to pass USE_FLASH. This will, like SDCARD, be 99% hardware related.

The option for "BLACKBOX" which is a feature should be added at some later point.

Going forward options for cloud building should be limited to "features". That way the if feature enabled / available in configurator can be used to identify if the build contains that feature as per the changes @haslinghuis has made.

NOTE: I have made provision in the API for backwards compatibility for 4.4.0. As FLASH was on for the default anyway, no one should notice its removal.

[github-actions]

Do you want to test this code? Here you have an automated build:
Assets
WARNING: It may be unstable. Use only for testing! See: https://www.youtube.com/watch?v=I1uN9CN30gw for instructions for unified targets!

[blckmn]

AUTOMERGE: (FAIL)

• github identifies PR as mergeable -> FAIL
• assigned to a milestone -> PASS
• cooling off period lapsed -> FAIL
• commit count less or equal to three -> PASS
• Don't merge label NOT found -> PASS
• at least one RN: label found -> PASS
• Tested label found -> FAIL
• assigned to an approver -> PASS
• approver count at least three -> FAIL

[blckmn]

Merged because with the option gone in configurator, then people will wonder why their flash is not enabled.