Update Scala API links to version 2.13.18 (#2551)

Author: pjfanning

scripts/link-validator.conf

@@ -51,10 +51,10 @@ site-link-validator {
   ignore-prefixes = [
     ## GitHub will block with "429 Too Many Requests"
     "https://github.com/"
-    "https://www.scala-lang.org/api/2.13.17/scala/runtime/AbstractFunction1.html"
-    "https://www.scala-lang.org/api/2.13.17/scala/runtime/AbstractFunction2.html"
-    "https://www.scala-lang.org/api/2.13.17/scala/runtime/AbstractFunction3.html"
-    "https://www.scala-lang.org/api/2.13.17/scala/runtime/AbstractPartialFunction.html"
+    "https://www.scala-lang.org/api/2.13.18/scala/runtime/AbstractFunction1.html"
+    "https://www.scala-lang.org/api/2.13.18/scala/runtime/AbstractFunction2.html"
+    "https://www.scala-lang.org/api/2.13.18/scala/runtime/AbstractFunction3.html"
+    "https://www.scala-lang.org/api/2.13.18/scala/runtime/AbstractPartialFunction.html"
     ## Bug, see https://github.com/scala/bug/issues/12807 and https://github.com/lampepfl/dotty/issues/17973
     "https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/nio/file/StandardOpenOption$.html"
   ]