fix(api): be more thorough with checking if secret management is enabled

[krancour]

cc @Marvin9 thanks for finding.

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 29 lines in your changes missing coverage. Please review.

Project coverage is 50.90%. Comparing base (447ccc5) to head (217b825). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/api/create_or_update_resource_v1alpha1.go	0.00%	7 Missing :warning:
internal/api/create_resource_v1alpha1.go	0.00%	7 Missing :warning:
internal/api/delete_resource_v1alpha1.go	0.00%	7 Missing :warning:
internal/api/create_credentials_v1alpha1.go	0.00%	4 Missing :warning:
internal/api/delete_credentials_v1alpha1.go	0.00%	1 Missing :warning:
internal/api/get_credentials_v1alpha1.go	0.00%	1 Missing :warning:
internal/api/list_credentials_v1alpha1.go	0.00%	1 Missing :warning:
internal/api/update_credentials_v1alpha1.go	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2973 +/- ## ========================================== - Coverage 50.91% 50.90% -0.01% ========================================== Files 279 279 Lines 25175 25178 +3 ========================================== Hits 12818 12818 - Misses 11666 11669 +3 Partials 691 691 ```

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