CI: install any new portal dependencies if needed

Install any new portal dependencies in CI. These may be needed for
running the API tests if the dependencies of the portal have
changed since the Docker image was last built.

.github/workflows/api-and-integration-tests.yml

@@ -85,6 +85,7 @@ jobs:
         cd yoda/docker/compose
         docker exec portal.yoda sh -c 'set -x ; cd /var/www/yoda && git config remote.origin.fetch  "+refs/heads/*:refs/remotes/origin/*" && git pull'
         docker exec portal.yoda sh -c 'set -x ; cd /var/www/yoda && git checkout ${{ steps.extract_branch.outputs.branch }} || git checkout development'
+        docker exec portal.yoda sh -c 'set -x ; cd /var/www/yoda && . venv/bin/activate && venv/bin/pip3 install -r requirements.txt'
         docker exec portal.yoda sh -c 'set -x ; cd /var/www/yoda && git status'
         docker exec portal.yoda sh -c 'set -x ; touch /var/www/yoda/*.wsgi'