Bump ws from 8.20.0 to 8.21.0 in /backend

Bumps [ws](https://github.com/websockets/ws) from 8.20.0 to 8.21.0.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](https://github.com/websockets/ws/compare/8.20.0...8.21.0)

---
updated-dependencies:
- dependency-name: ws
  dependency-version: 8.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/package-lock.json

@@ -22,7 +22,7 @@
         "rust-gbt": "file:./rust-gbt",
         "socks-proxy-agent": "~7.0.0",
         "typescript": "~4.9.3",
-        "ws": "~8.20.0"
+        "ws": "~8.21.0"
       },
       "devDependencies": {
         "@types/compression": "^1.7.2",
@@ -7193,9 +7193,9 @@
       }
     },
     "node_modules/ws": {
-      "version": "8.20.0",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.0.tgz",
-      "integrity": "sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA==",
+      "version": "8.21.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.21.0.tgz",
+      "integrity": "sha512-Vsp28b7DRcimFQvrqu2Wek3z1iYxDCWqHYB8Qsnk/S4RfaCQzPGPyBNuVjJV3cd6UiKtUtp6sNM77gWvzcCH+g==",
       "engines": {
         "node": ">=10.0.0"
       },
@@ -12234,9 +12234,9 @@
       }
     },
     "ws": {
-      "version": "8.20.0",
-      "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.0.tgz",
-      "integrity": "sha512-sAt8BhgNbzCtgGbt2OxmpuryO63ZoDk/sqaB/znQm94T4fCEsy/yV+7CdC1kJhOU9lboAEU7R3kquuycDoibVA==",
+      "version": "8.21.0",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.21.0.tgz",
+      "integrity": "sha512-Vsp28b7DRcimFQvrqu2Wek3z1iYxDCWqHYB8Qsnk/S4RfaCQzPGPyBNuVjJV3cd6UiKtUtp6sNM77gWvzcCH+g==",
       "requires": {}
     },
     "y18n": {

backend/package.json

@@ -53,7 +53,7 @@
     "redis": "^4.7.0",
     "socks-proxy-agent": "~7.0.0",
     "typescript": "~4.9.3",
-    "ws": "~8.20.0"
+    "ws": "~8.21.0"
   },
   "devDependencies": {
     "@types/compression": "^1.7.2",