Sync opencv-color-spaces with the updated tutorial

[realpython-bot]

Maintenance sync for the tutorial Image Segmentation Using Color Spaces in OpenCV + Python.

What changed

• finding-nemo.py: print flags[84] instead of flags[40]. On OpenCV 5.0 there are 374 COLOR_ flags, and COLOR_BGR2RGB now sits at index 84 (index 40 is COLOR_BAYER_GR2GRAY). This matches the updated article.
• New requirements.txt with the same pins as the article's updated dependencies: opencv-python==5.0.0.93, numpy==2.5.3, matplotlib==3.11.2.

Article draft: https://realpython.com/pbjt/blog/post/2423/change/
Maintenance card: https://trello.com/c/hFARsVkR

Verification

• Fresh Python 3.14 venv from requirements.txt, then ran MPLBACKEND=Agg python finding-nemo.py against the bundled images: exits 0 and prints 374 flags total: / COLOR_BGR2RGB.
• ruff@0.14.1 format --check and ruff@0.14.1 check pass on the folder.

🤖 Generated with Claude Code