fix(ci): sync test-minimum-versions job with current pyproject.toml minimums

[the-mace]

Summary

• After PRs deps(deps-dev): update pytest requirement from >=8.2.0 to >=8.4.2 #11 (pytest >=8.4.2), deps(deps): update click requirement from >=8.1.0 to >=8.3.2 #12 (click >=8.3.2), and deps(deps): update httpx requirement from >=0.27.0 to >=0.28.1 #15 (httpx >=0.28.1) bumped the declared minimum versions in pyproject.toml, the hardcoded pin versions in the test-minimum-versions CI job were never updated
• This caused the job to install versions below the declared minimums, making the test meaningless
• Updates: httpx==0.27.0→0.28.1, click==8.1.0→8.3.2, pytest==8.2.0→8.4.2

Test plan

• CI test-minimum-versions job runs with the correct minimum versions matching pyproject.toml
• All 58 existing tests continue to pass (verified locally)

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