Make gen_requirements_all.py case insensitive for ignored packages

[belidzs]

Description:

When I was working on implementing a new platform I have added RPi.GPIO to the requirements. It turns out this was actually a blacklisted component in gen_all_requirements.py but because I have accidentally wrote RPI.GPIO instead (same component, different case) it got added to requirements_all.txt anyway.

This caused pylint to fail on a completely different, but already approved component in the dev branch (rpi_gpio). Since it took a while to track down this problem I figured I might as well fix gen_requirements_all.py to ignore case when matching against blacklisted packages.

Related issue (if applicable): #30837

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly. Update and include derived files by running python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.