No need to set WSLENV variable in Cygwin code as it can be set outside

Author: Blackhex

winsup/testsuite/cygrun.sh

@@ -14,6 +14,5 @@ then
     $cygrun "$exe -v -cygwin $windows_runtime_root/cygwin1.dll"
 else
     # Removing cygdrop $cygrun to make the tests pass while testing on wsl-env
-    WSLENV="$WSLENV:PATH/p" \
     $exe
 fi