Update a link to Scala Language Specification from version 2.12 to version 2.13

Author: ShapelessCat

docs/docs/reference/metaprogramming/inline.md

@@ -33,7 +33,7 @@ object Logger {
 The `Config` object contains a definition of the **inline value** `logging`.
 This means that `logging` is treated as a _constant value_, equivalent to its
 right-hand side `false`. The right-hand side of such an `inline val` must itself
-be a [constant expression](https://scala-lang.org/files/archive/spec/2.12/06-expressions.html#constant-expressions).
+be a [constant expression](https://scala-lang.org/files/archive/spec/2.13/06-expressions.html#constant-expressions).
 Used in this way, `inline` is equivalent to Java and Scala 2's `final`. Note that `final`, meaning
 _inlined constant_, is still supported in Dotty, but will be phased out.