Update to Volto 16.30.1 and Plone 6.0.9

[fredvd]

This PR mainly updates Plone 6 and Volto 16 minor versions, at least that's where I started :-$ .

Further it adds tooling to use a local filestorage based content dump instead of having to start a postgresql instance, that would need a postgresql dump restored to work locally with the plone.org content data. the idea is to create a slimmed down version of the plone.org website, create a filestorage/blobstorage tar.gz and pass these to community members who want to help with plone.org technical maintenance and development.

When testing locally I found a problem with the volto-slider-block: the 4 slides on the homepage loose the related image. When I edit the page and relink the images, they work again. Is this a known issue that is caused by the Volto 16 minor update? We might step from 16.19 to 16.30 here, the 16.25 update from David was maybe not deployed yet.
If we only use the slider on the homepage it's a small manual fix, but I'm still intrigued this would happen to the slider block. I tried updating volto-slider-block to the latest 4.x version 4.3.0, doesn't improve the related background image breaking.

detailed changes:
Update to Plone backend 6.0.9
Update volto-slider-block to latest minor in same major release Update volto-matomo to latest minor in same major release. Add alternative filestorage based configuration profile Add zodbconvert example and instructions in devops/zodbconvert Use mxdev 3.1.0 and pip 23.3.2
Update docker-compose example
List and pin backend bootstrap packages in backend/requirements-bootstrap.txt

[sneridagh]

@fredvd take a look at the peer dependency of the slider versions. Could be that version is only Volto 17 compat. Also: heads up, VLT is Volto 17 onwards only compatible!

The rest LGTM

[fredvd]

take a look at the peer dependency of the slider versions. Could be that version is only Volto 17 compat.

I checked the slick dependences, but not much has moved there. I did just see another traceback when I load the homepage locally from the node.js process, I'll create a separate ticket out of the slider block issue and merge this branch, then we can inspect it on testing.

Also: heads up, VLT is Volto 17 onwards only compatible!

Yes I'm aware of that, thanks for mentionning. I wanted to first get to latest Volto 16.x to have that in place for small maintenance for the next weeks/month and then do a spike/test with Volto 17 and VLT.