adds an alien lab ruin to icemeta underground (#22541)

* i hope this is it

* Update config/iceruinblacklist.txt

Co-authored-by: Byemoh <[email protected]>

* Update icemoon_underground_alien_lab.dmm

* noops

* Update _maps/RandomRuins/IceRuins/icemoon_underground_alien_lab.dmm

Co-authored-by: AMyriad <[email protected]>

* amyriad roofing changes

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Co-authored-by: Byemoh <[email protected]>
Co-authored-by: AMyriad <[email protected]>

Author: 3 people