fix: Traffic-Sign-Detection/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CERTIFI-5805047

Author: snyk-bot

Traffic-Sign-Detection/requirements.txt

@@ -8,7 +8,7 @@ audioread==2.1.9
 backcall==0.2.0
 bleach==3.2.1
 cachetools==4.2.0
-certifi==2020.12.5
+certifi==2023.7.22
 cffi==1.14.4
 chardet==4.0.0
 colorama==0.4.4