PIPE-2738: update processing environment screenshots in weblog guide
Replace the single, lower-resolution `processing_env_2024.png` with two new,
higher-resolution screenshots (`weblog_runtime_env1.png` and `weblog_runtime_env2.png`)
for the Processing Environment popup window.
The layout is updated to display the two images side-by-side using an HTML
flexbox container and Sphinx `image` directives to ensure they are properly
sized, centered, and readable.
