Update alpine image version in `static QA` job to 3.12.0
What does this MR do?
This MR updates the static QA job image.
Why was this MR needed?
Other jobs have been upgraded to version 3.12 of alpine, so by keeping the images at the same version, we stand to take advantage of the Docker image layer cache.
What's the best way to test this MR?
What are the relevant issue numbers?
Edited by Georgi N. Georgiev