fix: pin cross to v0.2.4 for compatibility with rustc 1.85.0

The latest cross version (0.2.5) requires rustc 1.92.0+, but the
project uses rustc 1.85.0 as specified in rust-toolchain.toml.
This change pins cross to v0.2.4 which is compatible with rustc 1.85.0.

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

Author: Mossaka

scripts/setup-cross.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
-cargo install cross --git https://github.com/cross-rs/cross
+# Pin to v0.2.4 which supports rustc 1.85.0
+# v0.2.5 requires rustc 1.92.0+
+cargo install cross --git https://github.com/cross-rs/cross --tag v0.2.4
 
 if [ ! -z "$CI" ]; then