[py] Fix test for CONDA_PREFIX in selenium_manager

[mweinelt]

Fix test for CONDA_PREFIX in selenium manager, which regressed in 4.12.0.

Description

Accessing CONDA_PREFIX in os.environ fails with a KeyError when it is not set. The condition should instead check for the existence of the key, before accessing it in the following codepath.

Fixes: d4285d1 ("fix for conda install of selenium-manager (#12536)")

Motivation and Context

Traceback (most recent call last):
 File "/nix/store/jdm5chqkmh3z0wbip7r165fas3bfg1y4-python3-3.11.5-env/lib/python3.11/site-packages/selenium/webdriver/common/driver_finder.py", line 38, in get_path
   path = SeleniumManager().driver_location(options) if path is None else path
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 File "/nix/store/jdm5chqkmh3z0wbip7r165fas3bfg1y4-python3-3.11.5-env/lib/python3.11/site-packages/selenium/webdriver/common/selenium_manager.py", line 78, in driver_location
   args = [str(self.get_binary()), "--browser", browser]
               ^^^^^^^^^^^^^^^^^
 File "/nix/store/jdm5chqkmh3z0wbip7r165fas3bfg1y4-python3-3.11.5-env/lib/python3.11/site-packages/selenium/webdriver/common/selenium_manager.py", line 57, in get_binary
   if not path.is_file() and os.environ["CONDA_PREFIX"]:
                             ~~~~~~~~~~^^^^^^^^^^^^^^^^
 File "<frozen os>", line 679, in __getitem__
KeyError: 'CONDA_PREFIX'

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[CLAassistant]

All committers have signed the CLA.

[titusfortner]

So this never actually worked?

I think the plan is to remove this functionality entirely now that people can set SE_MANAGER_PATH to point to the location of the selenium manager. Either the user can set it or the package manager can set it.

[titusfortner]

Thank you for the PR.

Between this and #13076 it appears this was not working, so I'm removing it.

The correct fix now is for the location of the Selenium Manager binary to be specified in SE_MANAGER_PATH environment variable. Ideally this can be added by the anaconda project by default.