fix: engines/arachni/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-URLLIB3-14896210
- https://snyk.io/vuln/SNYK-PYTHON-WERKZEUG-14908843

Author: snyk-bot

engines/arachni/requirements.txt

@@ -22,6 +22,6 @@ pytest==3.8.1
 requests==2.28.2
 scandir==1.9.0
 six==1.11.0
-urllib3==1.26.5
-werkzeug==2.2.3
+urllib3==2.6.3
+werkzeug==3.1.5
 setuptools==65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability