This fixes 3c514224

Since nginx 1.25.1 ssl directive has been dropped, so fix the configuration
template to work with 1.25.2.

Update nginx-push-stream to follow nginx API changes.

Will support zlib 1.3+

Extend PATH to make xzcat available.

Extend PATH to make xzcat available.

Enforce python3 usage, as the newer version requires python3.

After the changes in 565f4986, Flask need recent version of MarkupSafe
so we must align the version of MarkupSafe and Flask.

1c4a3c69 (stack/slapos.cfg: version up eggs (requests 2.31.0 and
friends), 2023-10-04) broke component/nxdtest/test-py2.cfg and
others using pytest on python2

This part of 30804165 (component/apache-php: add missing xz in PATH,
2023-10-17) was pushed accidentally

This is required for xz archives