Add cleanup for temporary directory

Previously the temporary directory was removed via the RETURN trap
but this could be bypassed if the script exited early. Now we
explicitly clean up the directory in all exit paths.

openbao/install.sh

@@ -119,12 +119,12 @@ install_or_upgrade_bao() {
   log_info "Downloading OpenBao ${tag} (${arch}) from ${url}..."
 
   tmpdir=$(mktemp -d)
-  trap 'rm -rf "$tmpdir"' RETURN
   curl -fsSL "$url" -o "${tmpdir}/bao.tar.gz"
   tar -xzf "${tmpdir}/bao.tar.gz" -C "$tmpdir"
 
   if [[ ! -f "${tmpdir}/bao" ]]; then
     log_error "Archive did not contain expected 'bao' binary."
+    rm -rf "$tmpdir"
     exit 1
   fi
 
@@ -149,6 +149,8 @@ install_or_upgrade_bao() {
     log_info "Restarting openbao service..."
     rc-service openbao start
   fi
+
+  rm -rf "$tmpdir"
 }
 
 # ============================================================