Elixir CI

feat: make library JSON implementation independant #479

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Run time

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Job	Run time
build (1.14.1, 25)	1m 36s
build (1.15, 26)	1m 33s
build (1.16, 26)	1m 30s
build (1.17, 27, true)	1m 28s
	6m 7s