fix: requirements.txt to reduce vulnerabilities (#515)
fix: requirements.txt to reduce vulnerabilities (#515)

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-NLTK-1053952
- https://snyk.io/vuln/SNYK-PYTHON-NLTK-1660190
- https://snyk.io/vuln/SNYK-PYTHON-NLTK-1932014
- https://snyk.io/vuln/SNYK-PYTHON-NLTK-2313655
- https://snyk.io/vuln/SNYK-PYTHON-NLTK-460224
- https://snyk.io/vuln/SNYK-PYTHON-UJSON-2359034
- https://snyk.io/vuln/SNYK-PYTHON-UJSON-2940619
- https://snyk.io/vuln/SNYK-PYTHON-UJSON-2942122
- https://snyk.io/vuln/SNYK-PYTHON-URLLIB3-1014645
- https://snyk.io/vuln/SNYK-PYTHON-URLLIB3-1533435

Co-authored-by: snyk-bot <6524ae312692b75c8ed05087d0aa3c757ac39348@snyk.io>
csirtgadgets/bearded-avenger,csirtgadgets/bearded-avenger,csirtgadgets/bearded-avenger,csirtgadgets/bearded-avenger