[Choreo] Fix intelligent routing availability after deleting and re-creating an API

[chathuranga95]

Purpose

This PR,

• Removes unwanted minor version based intelligent routing regex building for the envoy router
• Fixes a bug where the vhost is neglected on API undeployment

Issues

Addresses: https://github.com/wso2-enterprise/choreo/issues/28419

Automation tests

• Unit tests added: No
• Integration tests added: No

Tested environments

OS: ubuntu Go: 1.22

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Maintainers: Check before merge

• [ ] Assigned 'Type' label
• [ ] Assigned the project
• [ ] Validated respective github issues
• [ ] Assigned milestone to the github issue(s)