Revert "Highlight conflicting param-env candidates"
This reverts #98794, commit 08135254dcf22be0d5661ea8f75e703b29a83514.
Seems to have caused an incremental compilation bug. The root cause of the incr comp bug is somewhat unrelated but is triggered by this PR, so I don't feel comfortable with having this PR in the codebase until it can be investigated further. Fixes#99233.