fix: samples/spookyshots/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-PROTOBUF-10364902

Author: snyk-bot

samples/spookyshots/requirements.txt

@@ -4,3 +4,4 @@ python-dotenv
 streamlit_option_menu
 tornado>=6.4.2 # not directly required, pinned by Snyk to avoid a vulnerability
 urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability
+protobuf>=4.25.8 # not directly required, pinned by Snyk to avoid a vulnerability