`:webp` modifier outputs same image for files with same name but different extensions

[shbchk]

When using the :webp modifier in a grid, files with the same name but different extensions (e.g., picture.jpg and picture.png) are processed into the same output image. Despite the images being different, ExpressionEngine renders them as identical when the :webp modifier is applied.

Steps to Reproduce:

• Upload two different images with the same filename but different extensions (e.g., testpic.jpg and testpic.png) in a grid.
• Apply the :webp modifier to both files.
• Observe that the output is the same for both images.

Original pictures:

Output:

[shbchk]

By the way, taking the opportunity, I’d like to remind about this feature request: #3635