This reverts commit 6c399134.

This is not really specific to python2, it is specific to ERP5, now that
ERP5 uses python3, the naming became not really good

With setuptools==67.8.0, pygolang does not install properly from
git clone for some reason. The issue seems to be that some DSOs
are not copied from build directory to target directory, such as
liblibgolang.so. They then fail to resolve at runtime.

With setuptools==44.1.1 it works.

pkgutil-resolve-name=1.3.10 requires flit_core as build backend.

This is used by component/slapos.

Use older numpy=1.22.0 to remain compatible with statsmodel=0.11.1.
Use older setuptools=44.1.1 to be able to install numpy=1.22.0.

dnspython=2.1.0 requires poetry as build backend.

Older Theia versions no longer compile inside test nodes since we
prevent using the system python.

Remove obsolete upgrade tests since we now upgrade from a Theia
version after merge request !1399.

Export (theia0) and export (theia1, ...) instances published
connection parameters twice, once without and once with the
resiliency connection parameters. Keep only that last one.

Use official SOAPpy=0.12.22 compatible with pip.
Downgrade zope.authentication=4.5.0 because 5.0 requires Python>=3.7.

Reverts 15871bbf

This commit is kept separate on purpose until nexedi/master is stable.

When using slapos.reboostrap to re-launch buildout with the version
of Python that was just installed, zc.buildout and its dependencies
are reinstalled for the new Python with the same egg versions. Thus
SRs which install Python 2 need to use Python-2-compatible versions
of setuptools, pip and wheel all along.

For this stack/slapos-py2.cfg is introduced.

In preparation to move all the

```
[openssl]
<= openssl-1.1
```

from individual Python2 SRs to a common stack/slapos-py2.cfg
introduced next.

This commit is kept separate on purpose until nexedi/master is stable.

Except for python2: keep beautifulsoup4=4.8.2.

beautifulsoup4=4.12.2 requires flit as build backend.

backcall=0.2.0 requires flit-core as build backend

entrypoints=0.3 rquires flit as build backend

pkgconfig=1.5.1 requires poetry as build backend.

Earlier version 1.22.0 does not support recent setuptools.

Latest version 1.26.2 has more complex build requirements,
left for later.

Now that buildout uses pip to correctly follow pyproject.toml,
cattrs=22.2.0 requires poetry as the build backend.

For now it's easier to install as wheel than to install poetry and
then use it as setup-egg for cattrs. This must be done eventually.

zc.buildout=2.7.1+slapos020 is SlapOS-patched buildout2 with support
for bootstrapping buildout3, required to be able to install buildout3.

Downgrade related eggs to pre-buildout3 versions as well.

Version up zc.buildout, pip and zc.recipe.egg.

Version up slapos.rebootstrap to adapt to buildout3.

See merge request !1587

Revert eb1b1a41 to avoid the use of
`fPIC` flag as it is a "contagious" build option.

To not face the build error "relocation R_X86_64_32 against
.rodata.str1.8 can not be used when making a shared object; recompile
with -fPIC" while building a shared library without fPIC flag, `gcc` is
compiled with `-enable-default-pie` flag (which is a compilation option
used for `gcc` binaries provided by Debian by example, see `gcc -v`).

Since slapos package provides gettext, it is not necessary to build
gettext here. Also slapos package's gettext commands such as msgfmt
may not work with libraries built by a software release, thus remove
LD_LIBRARY_PATH.