ci: Bump mutter image
Ever since the mutter image started to set up a non-root user for running tests, the toolbox image built on top of it has been broken.
The issue has now been addressed, so update the image to pull in the fix.
Ever since the mutter image started to set up a non-root user for running tests, the toolbox image built on top of it has been broken.
The issue has now been addressed, so update the image to pull in the fix.