remove pinned selenium version

Author: cleaaum

tests/requirements.txt

@@ -6,7 +6,7 @@ chromedriver-binary
 dash[dev, testing]==2.*
 ipdb
 percy
-selenium==4.0.0
+selenium
 flake8
 pylint==2.17.5;python_version>="3.7"
 pylint==2.9.*;python_version<"3.7"