[specs] new test case for model whose property is named "list"

[msyyc]

To cover scenario #9248, we need a new test case in https://github.com/microsoft/typespec/blob/main/packages/http-specs/specs/special-words/main.tsp that it has model property named "list"

NOTE:

• DO add changelog in https://github.com/microsoft/typespec/tree/main/.chronus/changes
• DO run command

  typespec/packages/http-specs/package.json

  Line 14 in 664978b

  "ci": "prettier specs --write && pnpm validate:all",

  under https://github.com/microsoft/typespec/blob/main/packages/http-specs to check all ci items.