`check-substrate` job fails due to `displaydoc` issue with the latest Rust nightly compiler

[Farhad-Shabani]

Summary

Context: #1099 (comment)

The check-substrate job for no_std check relies on nightly channel, which fails when running with latest nightly > 2024-02-27 compiler that accepted rust-lang/rust#120393. This should be resolved in yaahc/displaydoc#46.

As a temporary solution, we've set the NIGHTLY_VERSION to nightly-2024-02-24. It's worthwhile to explore whether it's essential to perform the no_std checks on the nightly channel.

[Manishearth]

Displaydoc 0.2.5 was published (yaahc/displaydoc#51) which should fix this error.

[rnbguy]

Awesome ! Works on latest nightlies ✨