fix: Properly mock OIDC responses

[kosciCZ]

Gets rid of the following warnings introduced in #35

tests/cmd/upload/test_oidc.py::test_put
  /home/mj/redhat/mobster/src/mobster/cmd/upload/oidc.py:232: RuntimeWarning: coroutine 'AsyncMockMixin._execute_mock_call' was never awaited
    response.raise_for_status()
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

tests/cmd/upload/test_oidc.py::test_post
  /home/mj/redhat/mobster/src/mobster/cmd/upload/oidc.py:253: RuntimeWarning: coroutine 'AsyncMockMixin._execute_mock_call' was never awaited
    response.raise_for_status()
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.61%. Comparing base (f297aa8) to head (6874935).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #49   +/-   ##
=======================================
  Coverage   97.61%   97.61%           
=======================================
  Files          26       26           
  Lines        1384     1384           
=======================================
  Hits         1351     1351           
  Misses         33       33           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.