ci: fix SeaweedFS binary permissions after artifact download

- Add step to chmod +x the weed binary after downloading artifacts
- Artifacts lose executable permissions during upload/download
- Prevents 'Permission denied' errors when Docker tries to run the binary

.github/workflows/spark-integration-tests.yml

@@ -125,6 +125,13 @@ jobs:
           ls -la
         fi
 
+    - name: Prepare SeaweedFS binary
+      run: |
+        echo "Making SeaweedFS binary executable..."
+        chmod +x docker/weed
+        ls -la docker/weed
+        echo "✓ Binary is ready"
+
     - name: Start SeaweedFS services
       working-directory: test/java/spark
       run: |
@@ -244,6 +251,13 @@ jobs:
           ls -la
         fi
 
+    - name: Prepare SeaweedFS binary
+      run: |
+        echo "Making SeaweedFS binary executable..."
+        chmod +x docker/weed
+        ls -la docker/weed
+        echo "✓ Binary is ready"
+
     - name: Cache Apache Spark
       id: cache-spark
       uses: actions/cache@v4