Custom kamelets are not fetched from private GitHub repository

[eshepelyuk]

What happened?

Using this guide
I am tryign to configure custom kamelet repository using private GitHub source repository.

According to this Zulip chat - I was trying to add GITHUB_TOKEN as env variable to operator pod, but operator doesn't work with private repositories.

Steps to reproduce

1. Create private / internal repository on GitHub
2. Put sample test kamelet inside a repository.
3. Generate PAT token.
4. Add PAT token as env variable to operator installation.
5. Add custom repository from 1st step as Kamelet catalog to IntegrationPlatform.

Relevant log output

{"level":"error","ts":"2024-02-21T15:46:52Z","msg":"Reconciler error","controller":"integration-controller","controllerGroup":"camel.apache.org","controllerKind":"Integration","Integration":{"name":"test-pipe","namespace":"camel"},"namespace":"camel","name":"test-pipe","reconcileID":"8204073e-7b1b-419a-8e39-ca43c202d0aa","error":"error during trait customization: kamelets trait execution failed: invalid character 'a' looking for beginning of value","stacktrace":"sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler\n\tsigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:324\nsigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem\n\tsigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:265\nsigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func2.2\n\tsigs.k8s.io/[email protected]/pkg/internal/controller/controller.go:226"}

### Camel K version

2.2.0