Update dependency urllib3 to v1.26.20

Author: renovate[bot]

requirements.txt

@@ -4,6 +4,6 @@ htmlmin==0.1.12
 Mako==1.2.4
 requests==2.32.3
 polib==1.1.1
-urllib3==1.26.19
+urllib3==1.26.20
 certifi>=2022.12.7 # not directly required, pinned by Snyk to avoid a vulnerability
 idna>=3.7 # not directly required, pinned by Snyk to avoid a vulnerability