[Bug]: could not use uri template in server endpoint

### Describe the bug

not able to allow reserved encoding for param in endpoint

### Reproduction

[playground](https://cadlplayground.z22.web.core.windows.net/?c=aW1wb3J0ICJAdHlwZXNwZWMvaHR0cCI7Cgp1c2luZyBUeXBlU3BlYy5IdHRwOwpAc2VydmljZSh7CiAgdGl0bGU6ICJXaWRnZXQgU8YbIiwKfSnGKWVyKCJ0ZXN0L3srcGFydH0iLCAixCZlciIsIMRCxBY6IHN0cmluZ8Q2bmFtZXNwYWNlIERlbW%2FHUTsKCm1vZGVsIMdoxDlAdmlzaWJpbGl0eSgicmVhZMRbdXBkYXRlIinEIHBhdGgKICBpZMhfOwoKICB3ZWlnaHQ6IGludDMyOwogIGNvbG9yOiAicmVkIiB8ICJibHVlIjsKfQoKQGVycm9yx3pFxAzFeWNvZGXLQG1lc3NhZ2XKZcQ6cm91dGUoIi935QCwcyIpCkB0YWco5wEoxBBpbnRlcmbkAOjHFMVcQOQA3mxpc3QoKTrHGVtdIHzGfsRuxSHkAO4o5QDg6wDeyTHNL3Bvc3QgY3JlYXRlKC4uLsYi1ythdGNoIOYBQt8sQGRlbGV0ZSDGB%2FQAi3ZvaWTNMucBEntpZH0vYW5hbHl6ZSIp5wCgxxDUSMYJykp9Cg%3D%3D&e=%40typespec%2Fopenapi3&options=%7B%22linterRuleSet%22%3A%7B%22extends%22%3A%5B%22%40typespec%2Fhttp%2Fall%22%5D%7D%7D)

### Checklist

- [X] Follow our [Code of Conduct](https://github.com/microsoft/typespec/blob/main/CODE_OF_CONDUCT.md)
- [X] Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
- [X] Check that this is a concrete bug. For Q&A open a [GitHub Discussion](https://github.com/Microsoft/typespec/discussions).
- [X] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.