Fix cronjob running on disabled snaps

[FrederikBolding]

Fixes an issue where cronjobs would still fire on disabled snaps. The cronjob wouldn't succeed as the snap was not allowed to run, but the CronjobController would try to run the cronjob regardless.

Fixes #1720

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (1d7a1ff) 95.79% compared to head (bfa8d2a) 95.79%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1743   +/-   ##
=======================================
  Coverage   95.79%   95.79%           
=======================================
  Files         240      240           
  Lines        5469     5474    +5     
  Branches      852      852           
=======================================
+ Hits         5239     5244    +5     
  Misses        230      230           

Files Changed	Coverage Δ
...snaps-controllers/src/cronjob/CronjobController.ts	97.08% <100.00%> (+0.11%)	⬆️
...ages/snaps-controllers/src/snaps/SnapController.ts	96.50% <100.00%> (+<0.01%)	⬆️

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[GuillaumeRx]

Small nit: You added the SnapUpdated event but I can't see where you are using it

Forget this comment, it was already in before this change.