Bump urllib3 from 1.26.8 to 2.6.3 in /requirements/py36-reqs

Bumps [urllib3](https://github.com/urllib3/urllib3) from 1.26.8 to 2.6.3.
- [Release notes](https://github.com/urllib3/urllib3/releases)
- [Changelog](https://github.com/urllib3/urllib3/blob/main/CHANGES.rst)
- [Commits](urllib3/urllib3@1.26.8...2.6.3)

---
updated-dependencies:
- dependency-name: urllib3
  dependency-version: 2.6.3
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/py36-reqs/docs.txt

@@ -445,7 +445,7 @@ tzlocal==4.1
     # via
     #   -r requirements/py36-reqs/install.txt
     #   dateparser
-urllib3==1.26.8
+urllib3==2.6.3
     # via
     #   -r requirements/py36-reqs/install.txt
     #   botocore

requirements/py36-reqs/install.txt

@@ -152,7 +152,7 @@ tzdata==2021.5
     # via pytz-deprecation-shim
 tzlocal==4.1
     # via dateparser
-urllib3==1.26.8
+urllib3==2.6.3
     # via
     #   botocore
     #   elasticsearch

requirements/py36-reqs/tests.txt

@@ -290,7 +290,7 @@ tzlocal==4.1
     # via
     #   -r requirements/py36-reqs/install.txt
     #   dateparser
-urllib3==1.26.8
+urllib3==2.6.3
     # via
     #   -r requirements/py36-reqs/install.txt
     #   botocore