docs: replacing Supporters Through time logos to match the GitHub themes - #1067

Description

Updated the Supporters Through Time section in the README to replace the LambdaTest logo with the TestMu AI logo and added theme-aware logos for both TestMu AI and Red Hat.

The README now displays the appropriate logo version based on the user's GitHub theme (light or dark).

Motivation behind this PR?

This PR updates the supporter logos to reflect the current sponsorship and improve visibility in both light and dark GitHub themes.

What type of change is this?

Documentation change.

AI Assistance Disclosure (REQUIRED)

• No AI tools were used in preparing this PR.
• If AI tools were used, I have disclosed which ones, and fully reviewed and verified their output.

Checklist

• A changelog entry was added, or this PR does not require one. Instructions
• Unit tests were added or updated as needed, or not required for this change. Instructions
• All unit tests pass locally. Instructions
• Docstrings or comments were added or updated as needed, or no documentation changes were required. Instructions
• This PR does not significantly reduce code or docstring coverage.
• Code follows the project’s style guidelines.
• ScanAPI was run locally and the changes were manually verified, or this was not necessary. Instructions

Issue

Closes #867