fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-INFLIGHT-6095116

Author: snyk-bot

package.json

@@ -53,7 +53,7 @@
     "deploy": "gatsby build --prefix-paths && gh-pages -d public"
   },
   "devDependencies": {
-    "eslint": "^5.10.0",
+    "eslint": "^9.0.0",
     "eslint-config-airbnb": "^17.1.0",
     "eslint-plugin-import": "^2.9.0",
     "eslint-plugin-jsx-a11y": "^6.0.3",