requirements.txt is mandatory

Description

the template requires a requirements.txt but imho this is a too strong assumption. I managed to hack it through the sphinx-pre-build.sh this way:

#!/usr/bin/env sh

set -e

apt-get update && apt-get install -y git
pip install uv
uv --version
uv export --no-emit-workspace --no-annotate --no-header --no-hashes --output-file requirements.txt
uv pip install -r requirements.txt --system

Implementation ideas

(If you have any implementation ideas, they can go here.) (Any design change proposal could be also discussed on the to be continuous Discord server.)