Update swagger parser to 2.1.28 #58

Job	Run time
Build Java Helidon (samples/client/petstore/java-helidon-client/v3/se, 17)	44s
Build Java Helidon (samples/client/petstore/java-helidon-client/v3/mp, 17)	42s
Build Java Helidon (samples/server/petstore/java-helidon-server/v3/se, 17)	39s
Build Java Helidon (samples/server/petstore/java-helidon-server/v3/mp, 17)	35s
Build Java Helidon (samples/server/others/java-helidon-server/v3/mp-format-test, 17)	31s
	3m 11s

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