Update workflow steps using action-rs in all workflow files

This is part of the "Fix GitHub Actions deprecations" epic, see [#365](https://github.com/stackabletech/issues/issues/365).

All `action-rs` actions need to be swapped out as they are no longer maintained, use an outdated `@actions/core` version and won't run on Node 16. It can be replaced with [dtolnay/rust-toolchain][1].

[1]: https://github.com/dtolnay/rust-toolchain