test/pyhttpd: move pyproject.toml and uv.lock under pyhttpd/

test/pyhttpd: move pyproject.toml and uv.lock under pyhttpd/

The pyproject.toml and uv.lock belong to the pyhttpd test suite, so move
them from test/ into test/pyhttpd/ where the package itself lives.

Update runtests-pyhttpd.sh to use 'uv sync --project pyhttpd/' and
reference the venv at pyhttpd/.venv/. Fix pyhttpd/env.py to look for
the venv at the same level (pyhttpd/.venv/) instead of the parent dir.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1934951 13f79535-47bb-0310-9956-ffa450edef68