test: CI test with DNS resolved feature is flaky

[u5surf]

Nevertheless the PR only be modified the README.md doc, the CI is failed which completely unrelated to the changes.
#2492

https://github.com/openresty/lua-nginx-module/actions/runs/23824388575/job/69443965578?pr=2492

#   Failed test 't/058-tcp-socket.t TEST 50: cosocket resolving aborted by coroutine yielding failures (require) - pattern "resolve name done" should match a line in error.log (req 0)'

058-tcp-socket.t is used an external DNS server which cause occasionally a communication failure

lua-nginx-module/t/058-tcp-socket.t

Line 13 in c81c951

$ENV{TEST_NGINX_RESOLVER} ||= '8.8.8.8';

Indeed it would be highly successful to be extended wait time but it cannot be solved fundamentally.

lua-nginx-module/t/058-tcp-socket.t

Line 3087 in c81c951

--- wait: 0.3

How can we solved it?