Uncap urllib3 version on Python < 3.10

urllib3 2.0 works with OpenSSL 1.1.1 and 3.0 on up-to-date builds of
Python 3.8 & 3.9.

setup.py

@@ -46,13 +46,6 @@ def run_tests(self):
     "PyYAML",
     "wrapt",
     "yarl",
-    # Support for urllib3 >=2 needs Python >=3.10
-    # so we need to block urllib3 >=2 for Python <3.10 for now.
-    # Note that vcrpy would work fine without any urllib3 around,
-    # so this block and the dependency can be dropped at some point
-    # in the future. For more Details:
-    # https://github.com/kevin1024/vcrpy/pull/699#issuecomment-1551439663
-    "urllib3 <2; python_version <'3.10'",
 ]
 
 tests_require = [