Wikipedia is a poor location to find biblical definitions.
“I establish My covenant with you; and all flesh shall never again be cut off by the water of the flood, neither shall there again be a flood to destroy the earth.””
Genesis 9:11 NASB1995
https://bible.com/bible/100/gen.9.11.NASB1995
The rainbow is a PROMISE to never take life on earth or destroy the earth by a FLOOD. it has nothing to do with protecting homosexuality.