Welcome to the Streamlit community, and thanks for sharing your deployment error! 
The error message E: Release file for http://deb.debian.org/debian-security/dists/bullseye-security/InRelease is expired (invalid since 8h 51min 59s) means the Debian security repository your app relies on has an expired release file, so apt-get can’t install dependencies from it. This is a server-side issue with the Debian repo, not your code or configuration.
This type of error has occurred before and is usually resolved automatically once the repository maintainers update the release file. You can try redeploying after some time. If the issue persists for more than a day, check the Streamlit Community Cloud status page or the forum for updates. No changes to your requirements.txt or packages.txt are needed unless you see other errors in the logs. If you want to share your repo or a minimal reproducible example, the community can help further! 
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