[bug#58086] [PATCH] gnu: Add fstrim-service-type.

[Bruno Victal]

Hi 宋文武,

I didn't notice this patch and ended up reimplementing another 
fstrim-service-type at [1].
Where we differ in the implementations:
* I didn't attempt to implement anacron capabilities, since I made the 
scheduling configurable.
* Uses define-configuration which can embed documentation and generate it for 
the manual.
* Slightly more “guix-y” style of configuration.


[1]: <https://issues.guix.gnu.org/61964>


Apologies for the duplicated effort!


Cheers,
Bruno