tox.ini: Quick-fix the CI for recent tox and recent urllib3

tox.ini

@@ -75,6 +75,8 @@ basepython = python3.7
 usedevelop=true
 commands =
     ./runtests.sh --cov=./vcr --cov-branch --cov-report=xml --cov-append {posargs}
+allowlist_externals =
+    ./runtests.sh
 deps =
     Werkzeug==2.0.3
     pytest
@@ -83,8 +85,9 @@ deps =
     PyYAML
     ipaddress
     requests: requests>=2.22.0
+    requests: urllib3<2
     httplib2: httplib2
-    urllib3: urllib3
+    urllib3: urllib3<2
     boto3: boto3
     boto3: urllib3
     aiohttp: aiohttp