unbreak windows worker build and retry cosign signing (#11926)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

.github/actions/sign-attest-image/action.yml

@@ -46,7 +46,15 @@ runs:
       env:
         IMAGE: ${{ inputs.image }}
         DIGEST: ${{ inputs.digest }}
-      run: cosign sign --yes --recursive "${IMAGE}@${DIGEST}"
+      # Fulcio and Rekor return transient 5xx often enough to fail a release;
+      # re-signing the same digest only adds a signature, so retrying is safe.
+      run: |
+        for attempt in 1 2 3 4 5; do
+          cosign sign --yes --recursive "${IMAGE}@${DIGEST}" && exit 0
+          echo "::warning::cosign sign failed (attempt $attempt/5)"
+          [ "$attempt" -lt 5 ] && sleep $((attempt * 30))
+        done
+        exit 1
 
     - name: SLSA provenance (GitHub artifact attestation)
       uses: actions/attest-build-provenance@v4

backend/windmill-worker/src/worker.rs

@@ -1055,6 +1055,7 @@ enum NsjailProbeError {
 fn probe_nsjail(nsjail_path: &str) -> Result<std::process::Output, NsjailProbeError> {
     // A fresh private directory: the worker runs what this config says, as itself.
     let dir = std::env::temp_dir().join(format!("windmill-nsjail-probe-{}", uuid::Uuid::new_v4()));
+    #[cfg_attr(not(unix), allow(unused_mut))]
     let mut builder = std::fs::DirBuilder::new();
     #[cfg(unix)]
     std::os::unix::fs::DirBuilderExt::mode(&mut builder, 0o700);