fix: Infinite authentication loop

[MoritzWeber0]

When the refresh token was expired, the backend sent the error "TOKEN_SIGNATURE_EXPIRED". The frontend did then request a new refresh token, leading to an infinite loop and a DDOS attack on our backend.

The error was accidentially added in #1569.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 80.66%. Comparing base (27e5007) to head (a1a0314).

Files	Patch %	Lines
...nd/capellacollab/core/authentication/basic_auth.py	0.00%	1 Missing :warning:
...acollab/core/authentication/provider/oauth/flow.py	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1622 +/- ## ========================================== + Coverage 80.64% 80.66% +0.01% ========================================== Files 185 185 Lines 6029 6035 +6 Branches 675 675 ========================================== + Hits 4862 4868 +6 Misses 1021 1021 Partials 146 146 ```

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[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud