Use fixed version for foundry for integration tests

Author: lutter

.github/workflows/ci.yml

@@ -173,7 +173,7 @@ jobs:
       - name: Install Foundry
         uses: foundry-rs/foundry-toolchain@82dee4ba654bd2146511f85f0d013af94670c4de # v1
         with:
-          version: nightly
+          version: v1.4.0
 
       - name: Install pnpm
         uses: pnpm/action-setup@a7487c7e89a18df4991f7f222e4898a00d66ddda # v4