fix: Ignore terminate calls to not executing Snaps

[FrederikBolding]

When a Snap fails to start we call terminateSnap (https://github.com/MetaMask/snaps/blob/main/packages/snaps-controllers/src/snaps/SnapController.ts#L3162), but this may fail if the Snap has not fully started.

To prevent logging unnecessary errors to Sentry, this PR allows calls to terminateSnap even if the Snap is not currently executing, if no job is found the we just return early.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.27%. Comparing base (53180b4) to head (449b9da).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3559   +/-   ##
=======================================
  Coverage   98.27%   98.27%           
=======================================
  Files         417      417           
  Lines       11758    11758           
  Branches     1827     1827           
=======================================
  Hits        11555    11555           
  Misses        203      203           

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