[Feature]: Remove unnecessary checks from screener code

[ralucapelin]

Library

React / v8 (@fluentui/react)

Describe the feature that you would like added

With the changes from #24292, the skipScreener environment variable can now be used to determine whether a screener check should be run or not, so other redundant checks and usage of other environment variables can be discarded.

Have you discussed this feature with our team

ling1726

Additional context

No response

Validations

• [X] Check that there isn't already an issue that request the same feature to avoid creating a duplicate.