fix(python): compare pkg names from poetry.lock and pyproject.toml in lowercase

[DmitriyLewen]

Description

There are cases where package names from poetry.lock and pyproject.toml use different case.
e.g. pyproject.toml uses Flask, but poetry.lock uses flask
So we need to compare lowercase package names.

Related issues

• Close fix(poetry): handle package names in a case-insensitive manner #6817

Checklist

• I've read the guidelines for contributing to this repository.
• I've followed the conventions in the PR title.
• I've added tests that prove my fix is effective or that my feature works.
• I've updated the documentation with the relevant information (if needed).
• I've added usage information (if the PR introduces new options)
• I've included a "before" and "after" example to the description (if the PR is a user interface change).

[knqyf263]

@aqua-bot backport release/v0.52

[aqua-bot]

Backport PR created: #6878