The only way they never go outside of the author's personal computer is if the author squashes (or discards!) them before pushing. Otherwise, they will go outside of the author's personal computer.
However, they will never be a head outside of the author's personal computer, because they are pushed along with later commits that fix the brokenness. CI only ever builds heads, so the existence of the broken commits doesn't matter.
However, they will never be a head outside of the author's personal computer, because they are pushed along with later commits that fix the brokenness. CI only ever builds heads, so the existence of the broken commits doesn't matter.