build(deps): bump soupsieve from 2.8.3 to 2.8.4 (#104)

Fixes the Dependency audit CI failure on main: soupsieve 2.8.3 carries
CVE-2026-49476 and CVE-2026-49477, both resolved in 2.8.4. Transitive
via beautifulsoup4; lockfile-only change, no pyproject constraint edits.
Verified locally with the workflow's exact pip-audit invocation:
no known vulnerabilities found.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: ayhammouda