[release-1.8] fix(techdocs): use correct type for additionalAllowedUriProtocols

[karthikjeeyar]

Description

The code for allowined additional uri protocols in techdocs clearly expects a string[] but the schema specifies string, this change brings the schema in line with the code

Consuming code

Which issue(s) does this PR fix

• Fixes
  https://issues.redhat.com/browse/RHDHBUGS-2808

PR acceptance criteria

Please make sure that the following steps are complete:

• GitHub Actions are completed and successful
• Unit Tests are updated and passing
• E2E Tests are updated and passing
• Documentation is updated if necessary (requirement for new features)
• Add a screenshot if the change is UX/UI related

How to test changes / Special notes to the reviewer

[github-actions]

Image was built and published successfully. It is available at:

• quay.io/rhdh-community/rhdh:pr-4399
• quay.io/rhdh-community/rhdh:pr-4399-40ac582a

[karthikjeeyar]

Verified this PR image quay.io/rhdh-community/rhdh:pr-4399-40ac582a with following config in rhdh-local, RHDH application boots up without any schema errors.

techdocs:
    builder: local
    generator:
      runIn: local
    publisher:
      type: local
    sanitizer:
      additionalAllowedURIProtocols: 
       - vscode

[kim-tsao]

/lgtm