They're not actually emoji; they're shortcodes that get rendered out to emoji in the Github interface. (Which, IMO, is worse than actually using emoji, but easier to type, I suppose.)

    935e922 (HEAD -> main, origin/main, origin/HEAD) :tada: Bump version number
    aeec220 (tag: v7) Merge branch 'feature/3d-noise'
    17fae26 :lipstick: Tweak labels
    a331736 :twisted_rightwards_arrows: Merge pull request #21 from Schneegans/feature/3d-noise

On Windows just press Win+; .

there's lessons on coursera and edx