We need to get rid of pkg_resources for py312. Fortunately,
we already use the load_pkg_resources() wrapper everywhere.
And, the tests of watchers already mock it. So, the general
mocking of pkg_resources was not doing anything, and this
patch simply deletes it.
Change-Id: Ifbdbbe18d6df6df377f0d914a097328d9c9e95ee