Update toolchain version

[arthurp]

As of writing the toolchain version is pinned to nightly-2025-02-01. Pinning this is good for build repeatability. However, causes some issue with dependencies that also use nightly. For example, as of nightly-2025-10-31 our version of unwind no longer builds:

error: unsafe attribute used without unsafe
  --> /root/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/unwinding-0.2.5/src/unwinder/arch/x86_64.rs:61:3
   |
61 | #[naked]
   |   ^^^^^ usage of unsafe attribute
   |
help: wrap the attribute in `unsafe(...)`
   |
61 | #[unsafe(naked)]
   |   +++++++     +

This can be an issue if some other crate requires a newer version of this crate.

Related to #5.

Enhancement Description

Update to a the new nightly and update dependency versions to support it.

Potentially also create a CI check which tries to build with the most recent nightly and creates an issue if it no longer builds. Someone may even have created an github action for this.