fix: upgrade multiple dependencies with Snyk

Snyk has created this PR to upgrade:
  - react from 18.2.0 to 18.3.0.
    See this package in npm: https://www.npmjs.com/package/react
  - react-dom from 18.2.0 to 18.3.0.
    See this package in npm: https://www.npmjs.com/package/react-dom

See this project in Snyk:
https://app.snyk.io/org/sswietoniowski/project/c4fde6b3-13e3-462b-b325-9990f3ceb289?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

projects/react/08_conference_speakers/package-lock.json

@@ -14,9 +14,9 @@
   "dependencies": {
     "axios": "^1.6.8",
     "next": "^14.2.3",
-    "react": "^18.2.0",
+    "react": "^18.3.0",
     "react-bootstrap": "^2.10.2",
-    "react-dom": "^18.2.0"
+    "react-dom": "^18.3.0"
   },
   "devDependencies": {
     "cross-env": "^7.0.3"