sonatype central (#270)

We migrated to sonatype central due to publishing problems, as
suggested by their support. Let's see if this works.

https://central.sonatype.com/

build.sbt

@@ -218,7 +218,7 @@ Global / cancelable           := true
 Global / onChangedBuildSource := ReloadOnSourceChanges
 
 ThisBuild / publishTo := sonatypePublishToBundle.value
-sonatypeCredentialHost := "s01.oss.sonatype.org"
+ThisBuild / sonatypeCredentialHost := xerial.sbt.Sonatype.sonatypeCentralHost
 ThisBuild / scmInfo := Some(
   ScmInfo(url("https://github.com/joernio/flatgraph"), "scm:[email protected]:joernio/flatgraph.git")
 )