Skip vulnerability scanning when SBOM Scan api is disabled

What does this MR do and why?

This MR modifies the run command to catch errors from vulnerability scanning when the dependency_scanning_sbom_scan_api feature flag is disabled. When this happens the error is swallowed and the execution continues without failing.

This allows us to do the folowing rollout strategy:

• set DS_ENABLE_VULNERABILITY_SCAN to true by default
• use the dependency_scanning_sbom_scan_api FF to gradually enable the sbom vulnerability scanning feature

This way we can monitor the rollout and turn the FF off if problems arise.

See full rollout plan in gitlab-org/gitlab#551861 (comment 2774664518)

Related issues

[FF] rollout `dependency_scanning_sbom_scan_api` (gitlab-org/gitlab#551861)

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