ci: 🎡 build site pages using short sha container image

To reflect most recent changes in base component when the pipeline builds the base component site pages, use the "short-sha" container image. The short-sha container image is the most immediate container image you have available in the pipeline. The "latest" image is produced after the short-sha container image, when a corresponding tag is created. Using the latest image here prevents site pages from having the most recent and you would need to run the pipeline again to have them.