[TT-12501] (bug): fix validation of API type

[buraksekili]

Description

Do not respect OAS field while checking API type (whether classic or OAS)

Related Issue

https://tyktech.atlassian.net/browse/TT-12501

Motivation and Context

Test Coverage For This Change

Screenshots (if appropriate)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] Make sure you are requesting to pull a topic/feature/bugfix branch (right side). If PRing from your fork, don't come from your master!
• [ ] Make sure you are making a pull request against our master branch (left side). Also, it would be best if you started your change off our latest master.
• [ ] My change requires a change to the documentation.
  • [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.
• [ ] Check your code additions will not fail linting checks:
  • [ ] gofmt -s -w .
  • [ ] go vet ./...
  • [ ] golangci-lint run

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud