test: remove TestWaitForFilesInotifyError

This "simple" approach of using LD_PRELOAD to inject errors when using
inotify no longer works on glibc 2.34 and it's now much more complicated,
as we can see in discussions from https://stackoverflow.com/questions/15599026/how-can-i-intercept-dlsym-calls-using-ld-preload
or code from https://gitlab.com/torkel104/libstrangle/-/commit/720f0ba2ce4423ce5f3e7ebe135e126007365bac

This test was for reproduction of a very specific problem that does not
happen so much on modern linux which has a much higher limit of inotify
watches, the easiest is to remove this test now.