pictures: Reduce size by 50% to avoid hitting gitlab limit
When deploying gitlab pages, we exceed the maximum size limit of our instance. See [1].
Right now, each board image is in 4k and uses more than 12MiB. Reduce the image sizes by 50% to have more reasonable size.
[1] https://gitlab.baylibre.com/baylibre/amlogic/atv/doc/-/pipelines/17830 Signed-off-by: Mattijs Korpershoek mkorpershoek@baylibre.com