refactor: remove osext dependency
What does this MR do?
Remove osext.
Why was this MR needed?
As of go 1.8+ Executable
is part of the std lib and osext is deprecated ( see https://github.com/kardianos/osext/issues/20 and https://github.com/kubernetes/kubernetes/issues/80127 )
What's the best way to test this MR?
What are the relevant issue numbers?
Could potentially fix #1246 (closed)