Stop using the fanotify-rs library

https://github.com/Serinalice/fanotify-rs/ which we are using right now seems unmaintained and there was no reaction to our pull requests.

Short term goal:

* write our own module for fanotify in lockc
* generate bindings to fanotify.h (maybe as an xtask similar to aya bindings?)

Long term goal:
* own crate