fix(ci): Trivy scan triggered when no scan requested

[khvn26]

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Changes

This fixes the build workflow failing for outside contributors.

How did you test this code?

This is a CI change.

[vercel]

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3 Skipped Deployments

Name	Status	Preview	Comments	Updated (UTC)
docs	⬜️ Ignored (Inspect)			Oct 16, 2024 4:34pm
flagsmith-frontend-preview	⬜️ Ignored (Inspect)			Oct 16, 2024 4:34pm
flagsmith-frontend-staging	⬜️ Ignored (Inspect)			Oct 16, 2024 4:34pm

[github-actions]

Docker builds report

Image	Build Status	Security report
ghcr.io/flagsmith/flagsmith-api-test:pr-4742	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-e2e:pr-4742	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-frontend:pr-4742	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-api:pr-4742	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith:pr-4742	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-private-cloud:pr-4742	Finished ✅	Results ✅

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.22%. Comparing base (2aad0a1) to head (118ccec).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4742   +/-   ##
=======================================
  Coverage   97.22%   97.22%           
=======================================
  Files        1172     1172           
  Lines       40516    40516           
=======================================
  Hits        39390    39390           
  Misses       1126     1126           

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