fix(ci): Authenticate Trivy correctly for ephemeral build

[khvn26]

Thanks for submitting a PR! Please check the boxes below:

• [x] I have run pre-commit to check linting
• [x] I have added information to docs/ if required so people know about the feature!
• [x] I have filled in the "Changes" section below?
• [x] I have filled in the "How did you test this code" section below?
• [x] I have used a Conventional Commit title for this Pull Request

Changes

This PR takes into account that Trivy action does not respect the host docker commands such as docker login.

How did you test this code?

This is a CI change.

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

3 Ignored Deployments

| Name | Status | Preview | Comments | Updated (UTC) | | :--- | :----- | :------ | :------- | :------ | | **docs** | ⬜️ Ignored ([Inspect](https://vercel.com/flagsmith/docs/HXpmJDHHdwTvnDpDsDgwfKEM63xX)) | | | Jun 25, 2024 1:34pm | | **flagsmith-frontend-preview** | ⬜️ Ignored ([Inspect](https://vercel.com/flagsmith/flagsmith-frontend-preview/3Ya4GPVTjBcdZUiBzwBy8gCN5c51)) | | | Jun 25, 2024 1:34pm | | **flagsmith-frontend-staging** | ⬜️ Ignored ([Inspect](https://vercel.com/flagsmith/flagsmith-frontend-staging/2phdzLTzRTCAPzdK5m1dbt4Jq9Li)) | | | Jun 25, 2024 1:34pm |

[github-actions[bot]]

Uffizzi Preview deployment-53465 was deleted.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 96.57%. Comparing base (fe7cc53) to head (3cee410).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #4227 +/- ## ======================================= Coverage 96.57% 96.57% ======================================= Files 1190 1190 Lines 38754 38754 ======================================= Hits 37426 37426 Misses 1328 1328 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.