chore: upgrade rust to 1.81

[tedim52]

Description

cargo publish is currently not working in CI due to the following error:

error: failed to verify package tarball

Caused by:
  package `home v0.5.11` cannot be built because it requires rustc 1.81 or newer, while the currently active rustc version is 1.70.0

CI image was using rust 1.70. I verified that cargo publish --dry-run fails on 1.78.0 locally but when works after updating to version 1.83

   Compiling tokio-io-timeout v1.2.0
   Compiling tokio-stream v0.1.17
   Compiling h2 v0.3.26
   Compiling tower v0.4.13
   Compiling hyper v0.14.32
   Compiling hyper-timeout v0.4.1
   Compiling tonic v0.9.2
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 20.45s
   Uploading kurtosis-sdk v2.0.0 (/Users/tewodrosmitiku/craft/kurtosis/api/rust)
warning: aborting upload due to dry run

Is this change user facing?

NO