chore: Remove the shell and docs for build/install APISIX on MacOS #15934

Job	Run time
build (ubuntu-20.04, linux_openresty, lua-resty-worker-events, t/plugin/[a-k]*)	29m 19s
build (ubuntu-20.04, linux_openresty, lua-resty-worker-events, t/plugin/[l-z]*)	29m 31s
build (ubuntu-20.04, linux_openresty, lua-resty-worker-events, t/admin t/cli t/config-center-yaml...	21m 46s
build (ubuntu-20.04, linux_openresty, lua-resty-worker-events, t/node t/pubsub t/router t/script ...	23m 14s
build (ubuntu-20.04, linux_openresty, lua-resty-events, t/plugin/[a-k]*)	29m 26s
build (ubuntu-20.04, linux_openresty, lua-resty-events, t/plugin/[l-z]*)	29m 40s
build (ubuntu-20.04, linux_openresty, lua-resty-events, t/admin t/cli t/config-center-yaml t/cont...	21m 34s
build (ubuntu-20.04, linux_openresty, lua-resty-events, t/node t/pubsub t/router t/script t/secre...	21m 55s
	3h 26m 25s

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