fix: Ensure os is prefixed in install deps (#999)

Author: sommeeeer

.changeset/orange-pots-clap.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+fix: Ensure os is prefixed in install deps

packages/open-next/src/build/installDeps.ts

@@ -34,7 +34,7 @@ export function installDependencies(
     const libcOption = installOptions.libc
       ? `--libc=${installOptions.libc}`
       : "";
-    const osOption = installOptions.os ? `--os=${installOptions.os}` : "linux";
+    const osOption = `--os=${installOptions.os ?? "linux"}`;
 
     const additionalArgs = installOptions.additionalArgs ?? "";
     const installCommand = `npm install ${osOption} ${archOption} ${targetOption} ${libcOption} ${additionalArgs} ${installOptions.packages.join(" ")}`;