chore: add rust-toolchain.toml file to pin Rust version

This ensures consistent Rust versions across environments and CI runs.

Signed-off-by: Lorenzo Bertin Salvador <lorenzobs@usp.br>

Author: lorenzoberts

rust-toolchain.toml

@@ -0,0 +1,4 @@
+# This file forces cargo commands run in the repository to follow the rust version contained here.
+# This is particulary useful to maintain consistency between workflow and local runs
+[toolchain]
+channel = "1.88.0"