rust-1.88: build with rust-1.87 instead of rust-1.86

Rust bootstraps with its most recent previous version.

Commit-message-by: Dan Watkins <daniel.watkins@chainguard.dev>
Signed-off-by: Ajay Kemparaj <ajaykemparaj@gmail.com>

Author: ajayk

rust-1.88.yaml

@@ -33,7 +33,7 @@ environment:
       - openssl-dev
       - patch
       - python3
-      - rust~1.86
+      - rust~1.87
       - samurai
       - wasi-libc
       - xz-dev