Update scala-library to 2.13.15 (#1040)

* Update scala-library to 2.13.15

* Update config.yml

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Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: svroonland <svroonland@users.noreply.github.com>

build.sbt

@@ -1,6 +1,6 @@
 import xerial.sbt.Sonatype.GitHubHosting
 
-val mainScala = "2.13.14"
+val mainScala = "2.13.15"
 val allScala  = Seq(mainScala, "3.3.4")
 
 val excludeInferAny = { options: Seq[String] => options.filterNot(Set("-Xlint:infer-any")) }