Bump dependencies of the project

This MR should:

• Bump Rust and tools to 1.80 nightly
• Use crane + fenix
• Use cargo-llvm-cov instead of the discontinued grcov

assigned to @v-lafeychine

created branch 115-improve-ci-by-using-nix to address this issue

mentioned in merge request !105 (merged)

changed title from Improve CI by using Nix to Bump dependencies of the project

changed the description

mentioned in commit 9fcf2ac9

closed with merge request !105 (merged)