prep 3.0.0-rc8 (#756)

Author: pjfanning

build.sbt

@@ -25,7 +25,7 @@ bomFormat := "xml"
 
 resolvers += Resolver.sonatypeCentralSnapshots
 ThisBuild / version := "3.0.0-SNAPSHOT"
-val jacksonVersion = "3.0.0-rc7"
+val jacksonVersion = "3.0.0-rc8"
 
 autoAPIMappings := true