chore(ci): bump rust toolchain to 1.81

[SuperFluffy]

Summary

Updates the rust toolchain used for all rust releated github jobs to and the containerfile to 1.81.0.

Background

Rust 1.81 was released and comes with a load of niceties that we would like to use. Among them of immediate interest are:

1. lint reasons (Replace all allow attributes by expect and require lint reasons #1521)
2. fixes clippy::blocks_in_conditions lint triggering on proc macros like tracing::instrument (which chore(sequencer): Add instrumentation #1368 needed to work around)
3. lazy lock and lazy cell (to replace once_cell) in 1.80 (Replace once_cell by sync primitives added in 1.80 #1520)
4. checked cfg names (also 1.80 which flags a few issues in our code and should be immediately available).

Note that this is orthgonal to setting the MSRV in individual Astria crates.

Changes

• Updates all github workflows to use the 1.81.0 toolchain (except for rustfmt and dylint, which need nightlies, respectively).
• Fix all new clippy warnings.
• Upgraded to the most recent dylint to make it compile again
• Upgrade the single containerfile to use rust:1.81-bookwarm as the base image

Related Issues

Closes #1522

[Fraser999]

I guess we could name this RUST_TOOLCHAIN to be consistent with the filename?

Also, could we read the appropriate value from the rust-toolchain.toml file here rather than having to keep these in sync?

[SuperFluffy]

RUSTUP_TOOLCHAIN is the actual env var that's read by rust: https://rust-lang.github.io/rustup/overrides.html#the-toolchain-file, so I'd like to keep that.

And I guess we could extract this, but I didn't want to move away from dtolnay/rust-toolchain (at least for now), and parsing toml files in workflows can only be done through obscure github actions, which I didn't feel comfortable introducing.

Followup?