refactor: remove dependence on apisix-base

[zll600]

The dependency should be apisix-base depends on apisix-nginx-module.

build-apisix-base.sh --> apisix-nginx-module

So we should not use build-apisix-base.sh in CI https://github.com/api7/apisix-nginx-module/blob/1345603d3b04b027cdae8254877af64f753ea7f3/.github/workflows/ci.yml#L41

A better way is to refer to CI of lua-resty-core to add a new script only for apisix-nginx-module. ref: https://github.com/openresty/lua-resty-core/blob/dc3fdd91b1abc2aac6706c9117a99cd2e00e6133/.travis.yml#L65