add a test to verify that release notes are using the good schema/link for banner images

[benoitf]

Task content

Release 1.23 generated an invalid entry in the release notes info data

https://github.com/podman-desktop/podman-desktop/blob/gh-pages/release-notes/1.23.json https://github.com/podman-desktop/podman-desktop/blob/gh-pages/release-notes/1.22.json

I think it did happened a lot of time in previous blog posts and it's breaking social media display of images

it's because the link is not really checked

We should have a unit test / or a shell script or whatever ensuring that for each blog post, if we enter an image link, it needs to resolve to the static folder path (it's not the same link that the inner hero image link that is then interpreted and we all fall into the trap)

so as it's quite hard to catch, need to introduce a check