Revert "Merge pull request #478 from Earlopain/bump-rust"

This reverts commit 89946d9, reversing
changes made to 7cb059d.

I chose an inopportune time to do this.

There is an upstream issue where builds on alpine arm64/v8 fail:
https://bugs.ruby-lang.org/issues/20506

Example failure: https://doi-janky.infosiftr.net/job/wip/job/new/job/build-arm64v8/45573/console

I believe rust-lang/rust#131221 will fix this
but it is only slated for Rust 1.83

Author: Earlopain