builds.sr.ht's FreeBSD image has golangci-lint 1.24, and we need Go
1.25. There's also very little advantage, as of right now, to have
multiple OSes in the CI.
hashAlgorithm's are assumed to be valid; methods on invalid
hashAlgorithms will panic from out-of-bounds read when it's not found in
hashAlgorithmTable and that's expected and intended.