Install openstacksdk version compatible with Alma8's Python 3.6

The openstacksdk Python package uses certain features only available in Python
3.8 since version 1.5.0 without advertising this to pip. See bug report at
https://storyboard.openstack.org/#!/story/2010903.

alma8/Dockerfile

@@ -14,5 +14,5 @@ RUN dnf update -y \
 RUN mkdir -p /py-venv \
  && python3 -m venv /py-venv/ROOT-CI \
  && /py-venv/ROOT-CI/bin/pip install --upgrade pip \
- && /py-venv/ROOT-CI/bin/pip install -r requirements-root.txt -r requirements-roottest.txt openstacksdk \
+ && /py-venv/ROOT-CI/bin/pip install -r requirements-root.txt -r requirements-roottest.txt openstacksdk==1.4.0 \
  && rm -f requirements-root.txt requirements-roottest.txt