ci: add explicit least permissions to workflows (#12813) #20599

Job	Run time
build (ubuntu-latest, linux_openresty, t/node t/pubsub t/router t/script t/secret t/stream-node t...	28m 31s
build (ubuntu-latest, linux_openresty, t/plugin/[a-k]*.t)	41m 9s
build (ubuntu-latest, linux_openresty, t/stream-plugin t/plugin/[l-z]*.t)	39m 2s
build (ubuntu-latest, linux_openresty, t/admin t/cli t/config-center-yaml t/control t/core t/debu...	27m 54s
	2h 16m 36s

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