It fixes some warnings when building the SWH documentation.

Related to swh/infra/sysadm-environment#5239

It's been migrated to the dynamic infra.

Refs. swh/infra/sysadm-environment#5237

Related to swh/meta#5075.

Refs. swh/infra/sysadm-environment#5215

Refs. swh/infra/sysadm-environment#5035

Refs. swh/infra/sysadm-environment#5214

Sphinx prints warnings when an extension does not declare it is safe to use
with parallel build and switch back to sequential build in that case.

Previously only parallel read warnings were filtered out so ensure parallel
write ones are also considered.

Refs. swh/infra/sysadm-environment#5069

Refs. swh/infra/sysadm-environment#5069

The accessible search is no longer running in moma nor search1.
Those services will be soon decommissionned.

Refs. swh/infra/sysadm-environment#5110

It's no longer the one running in moma which will soon be decommissioned.

Refs. swh/infra/sysadm-environment#5110

Refs. swh/infra/sysadm-environment#5069

Refs. swh/infra/sysadm-environment#5183

Refs. swh/infra/sysadm-environment#5110

Refs. swh/infra/sysadm-environment#5110

Refs. swh/infra/sysadm-environment#5211

Refs. swh/infra/sysadm-environment#5110

according to latest migrations as most were outdated.

Refs. swh/infra/sysadm-environment#5205

This reverts commit ef66ebd3.

Most were outdated.

Refs. swh/infra/sysadm-environment#5205

Related to swh/infra/sysadm-environment#5199

This reverts commit b358c3d2. This
update is not ready yet. Quoting pabs:

> […] I noticed that resubmitting a forge using the same URL and a
> different forge type is blocked with Request for forge already exists
> (id 240) when the forge was already added via Add Forge Now. So this MR
> will need to wait for a fix for that issue, or the process for
> submitting forge updates will need to be rethought.

Asked-in: https://archive.softwareheritage.org/admin/add-forge/request/155/

This is now used (esp. by swh-alter but it should be generalized) to
process svg images for publication.

it's not ready to be published.

Distribute these Makefiles in share/swh-docs and move the
glossary.rst in share/swh-docs/docs/devel to keep the directory hierarchy
of the source repo.