Upgrade nltk version from 3.9 to 3.9.4 to pick up updated click-8.1.9 to avoid vulnerability

[wnm3]

Vulnerability	Severity	CVSS	Dependency	Type	Fixed in (mellea version)	Remediation Possible**
CVE-2026-7246	High	7.2	click-8.1.8-py3-none-any.whl	Transitive	N/A*	❌

Vulnerability Severity Image CVSS Dependency Type Fixed in (mellea version) Remediation Possible**
CVE-2026-7246 Image High 7.2 click-8.1.8-py3-none-any.whl Transitive N/A* ❌

Type: Upgrade version

Origin: https://github.com/pallets/click/commit/c12c1490c28ae52c7f57a0efdfe35ce0e2a75b82

Release Date: 2026-04-30

Fix Resolution: click - 8.1.9,click - 8.1.9