Update Worker to use the new online key structure

[kairoaraujo]

This PR enables:

• The worker development and new release will use the new online key configuration
• The worker no longer uses custom run-ft*.sh scripts.
• Updates the docs not to use old local key configuration

The online key is now configured using the highly reliable signed TUF metadata, a feature fully supported by the new CLI admin Ceremony, Metadata Sign, and Update. This ensures a secure and efficient key configuration process.

Requires to merge first:

• [ ] https://github.com/repository-service-tuf/repository-service-tuf/pull/703/

[codecov[bot]]

Codecov Report

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

Project coverage is 100.00%. Comparing base (714a29d) to head (af4b0d5). Report is 38 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #513 +/- ## ========================================== Coverage 100.00% 100.00% ========================================== Files 15 15 Lines 1071 1207 +136 ========================================== + Hits 1071 1207 +136 ```

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