CI: Docker: fix binary permissions (#3)

Author: un-def

.github/workflows/release.yml

@@ -79,6 +79,7 @@ jobs:
           path: build
       - run: |
           mv dstack-sshproxy-* dstack-sshproxy
+          chmod +x dstack-sshproxy
         working-directory: build
       - name: Login to Docker Hub
         uses: docker/login-action@v4