fix: install cross from crates.io for rustc 1.85.0 compatibility

Installing cross from git causes cargo to resolve dependencies to their
latest compatible versions. Some of these (like home v0.5.12+) require
rustc 1.88+, which is incompatible with the project's rustc 1.85.0.

Cross v0.2.5 from crates.io uses locked dependencies that support the
published MSRV of rustc 1.58.1+, making it compatible with rustc 1.85.0.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: Mossaka

scripts/setup-cross.sh

@@ -1,5 +1,8 @@
 #!/bin/bash
-cargo install cross --git https://github.com/cross-rs/cross
+# Install cross from crates.io which has locked dependencies compatible with rustc 1.85.0
+# Installing from git causes cargo to resolve dependencies to latest versions,
+# some of which (like home v0.5.12+) require rustc 1.88+
+cargo install cross --version 0.2.5
 
 if [ ! -z "$CI" ]; then