Add OpenAPI spec for v2 Synthetics test result endpoints #17580

Job	Run time
pre-commit / pre-commit	1m 9s
test / test (3.2, ubuntu-latest)	1m 12s
test / test (jruby-9.4.12.0, ubuntu-latest)	2m 44s
test / test (2.7, ubuntu-latest)	1m 33s
examples / examples	2m 46s
report	7s
	9m 31s

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