chore: do not retry on bare HTTP 429 or HTTP 503

[jooola]

Related to #470

This is only a chore to prevent confusion with the now updated release-please commits in #470

We prefer not to retry requests:

• If the ingress returns a "bare" 429, as the backend was not able to respond anyway.
• If the ingress returns a "bare" 503, to prevent possible self-made DDoS, and preventing a disaster recovery.

[codecov[bot]]

Codecov Report

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

Project coverage is 71.54%. Comparing base (f7ac563) to head (fbafb2e).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #486 +/- ## ========================================== - Coverage 71.56% 71.54% -0.02% ========================================== Files 45 45 Lines 3903 3901 -2 ========================================== - Hits 2793 2791 -2 Misses 696 696 Partials 414 414 ```

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