chore(bootstrap): simplify bootstrap make target

The CI bootstrap steps weren't really "CI" related, nor were they
actually used. So they have been removed.

Brewfile.ci

@@ -1,3 +0,0 @@
-# frozen_string_literal: true
-
-brew 'python'

Makefile

@@ -46,16 +46,12 @@ SHELL := env \
 #
 
 bootstrap: bootstrap-brew bootstrap-ruby
-bootstrap-ci: bootstrap-brew bootstrap-brew-ci bootstrap-ruby bootstrap-pip
 
 bootstrap-ruby:
 	bundle install
 
 bootstrap-brew:
-	brew bundle
-
-bootstrap-brew-ci:
-	brew bundle --file Brewfile.ci
+	brew bundle --verbose --no-upgrade
 
 bootstrap-pip:
 	$(PIP) install -r requirements-ci.txt