[doc][macos] Add update-ci.sh for brew/pip3 updates

doc/macos-ci-install/update-ci.sh

+#!/usr/bin/env bash
+
+# Update CI installation
+echo "Updating homebrew..."
+brew update
+brew upgrade
+brew cleanup
+
+echo "Updating python packages..."
+pip=/usr/local/bin/pip3
+${pip} list --outdated --format=freeze | grep -v '^\-e' | cut -d = -f 1  | xargs -n1 ${pip} install -U