Add tests for pip install

[wing328]

a follow up pr to #23889

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• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
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  (For Windows users, please run the script in WSL)
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Summary by cubic

Add pip install -r requirements.txt to the Python Petstore samples workflow to install base deps before poetry install. This reduces CI failures and clarifies step names.

• Refactors
  • Added "Install via pip" step before installing poetry.
  • Renamed "Install" to "Install via poetry" for clarity.

^{Written for commit 8e9cc4f. Summary will update on new commits.}

Review in cubic

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}