Ensure images maintain aspect ratio on Drupal 9 upgraded site which adds width and height to HTML source of image output

Ensure all images retain aspect ratio, not just ones we size here.

Ensure images maintain aspect ratios on Drupal 9 upgraded site which adds width and height to HTML source of image output.

The correct solution here is to ensure anywhere you have an auto width or a percentage width in CSS, you also have an auto height.

Easiest way to do that is to have:

img {
  width: auto;
  height: auto;
}

so when later you might throw on a width: 100% or somesuch in your CSS, the height is already auto, which overrides the pixel dimensions in the height and width in HTML.