feat: set default value of `ssl_trusted_certificate` to `system` #17501

Job	Run time
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/plugin/[a-k]*)	34m 45s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/plugin/[l-z]*)	35m 6s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/admin t/cli t/config-center-yam...	24m 19s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/node t/pubsub t/router t/script...	24m 39s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/plugin/[a-k]*)	35m 9s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/plugin/[l-z]*)	36m 25s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/admin t/cli t/config-center-yaml t/con...	25m 8s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/node t/pubsub t/router t/script t/secr...	26m 22s
	4h 1m 53s

Provide feedback