[python] add test case for constant query

[msyyc]

GOAL:
add test case under https://github.com/microsoft/typespec/tree/main/packages/http-client-python/generator/test/generic_mock_api_tests and https://github.com/microsoft/typespec/tree/main/packages/http-client-python/generator/test/generic_mock_api_tests/asynctests for spector case https://github.com/microsoft/typespec/tree/main/packages/http-specs/specs/parameters/query which defines expected request and response.

NOTE:

• update

  typespec/packages/http-client-python/package.json

  Line 97 in a2c1939

  "@typespec/http-specs": "0.1.0-alpha.29",

  with dev version "https://www.npmjs.com/package/@typespec/http-specs/v/0.1.0-alpha.30-dev.1"
• DO remember add chanagelog
• You could refer to existing test case to understand how spector case work
• Before commit, run npm install && npm run build && npm run format under folder packages/http-client-python
• Remove outdated code

  typespec/packages/http-client-python/generator/test/generic_mock_api_tests/test_typetest_scalar.py

  Lines 56 to 58 in a2c1939

  	# open this test case after adopt new version of http-specs for https://github.com/microsoft/typespec/pull/8807
  	# def test_constant_query(client: ScalarClient):
  	# client.constant_query.post()