Install requirements for aliPublishS3 directly

This saves us from having to do a potentially-fragile "pip install" in every
publishing run.

publisher/provision.sh

@@ -2,8 +2,8 @@
 
 microdnf install -y epel-release  # for s3cmd
 microdnf update -y
-microdnf install -y shadow-utils git curl s3cmd rpm-build createrepo \
-         python3 python3-pip python3-setuptools rubygems
+microdnf install -y shadow-utils git curl s3cmd rpm-build createrepo rubygems \
+         python3 python3-pip python3-setuptools python3-requests python3-pyyaml python3-boto3
 alternatives --set python /usr/bin/python3
 
 gem install --no-document fpm