closes #5699
1.16.25 shipped with `ahash` 0.8.3 (yanked) 1.17.15 shipped with `ahash` 0.8.4 (build failure) main is already on `ahash` 0.8.7, but i only bumped to 0.8.5 to be conservative, which builds. closes #4761 closes #4762
closes #4107