fix(trait): report builder task strategy errors

[thedavidweng]

Fixes #6637

Running an Integration with builder.tasks and a non-pod build strategy moves the related IntegrationKit to Error, but the Integration only reports the generic kit error state.

The builder trait already sets a specific IntegrationKitTasksValid condition. However, the Integration status uses IntegrationKit.Status.Failure when appending the detailed failure reason, and this path was not populated for this builder trait failure.

Description

• Set IntegrationKit.Status.Failure when the builder trait reports a fatal IntegrationKit configuration error.
• Cover the builder.tasks plus routine build strategy path with unit assertions.
• Verify the Integration build-kit action includes the propagated failure reason in the Integration condition.

Release Note

fix(trait): Report builder task strategy errors on Integration status

[github-actions]

✔️ Unit test coverage report - coverage increased from 62.8% to 62.9% (+0.1%)

[squakez]

Nice fix! Thanks for the contribution!