request help: the key of the json in response_body is unordered

[tzssangglass]

Issue description

In a response body, if the body is in json format, the order of keys in json is unordered.
As a result, when executing test cases, many test cases that define the full response_body content or one that contains multiple keys fail to execute.
As follows

Environment

• apisix version (cmd: apisix version):master laster
• OS:centos7
• OpenResty:1.19.3.1-1.el7
• Test::Nginx:0.29

[tzssangglass]

It may be that the LuaJIT update in OpenResty:1.19.3.1 has caused the jsonencode results to change.
This problem is fixed in apisix with the PR (no merge to master yet): #2768

Temporary Fix: Reduce the version of OpenResty.

[spacewander]

#2768 can't be merged because there is a problem about the GitHub Action.
We will merge it after the problem is solved.
We are waiting for the solution.