fix: null-safe ExploreFeed eyebrow

[wized2]

section.eyebrow?.let { Eyebrow(it) }

[tyron12233]

Closing. Each of these !! follows an explicit null check on an immutable property, so it can't throw; the !! is only there because smart casts don't cross module boundaries. The change doesn't alter behavior, and several copies of it are duplicates or don't compile. Thanks for looking through the code.