Fix Scala.JS source map URIs

Dotty publishes release versions without a `v` in the tag, but the Scala.JS source map URI configuration is published with a `v` prefix. This causes incorrect source map URLs like: https://raw.githubusercontent.com/lampepfl/dotty/v3.1.0/library/src/scala/IArray.scala (this is in the current releases JAR).

This commit fixes the source map URIs to no longer use the `v` prefix.

Author: hugo-vrijswijk

project/Build.scala

@@ -828,7 +828,7 @@ object Build {
         if (isRelease) {
           val baseURI = (LocalRootProject / baseDirectory).value.toURI
           val dottyVersion = version.value
-          Seq(s"-scalajs-mapSourceURI:$baseURI->$dottyGithubRawUserContentUrl/v$dottyVersion/")
+          Seq(s"-scalajs-mapSourceURI:$baseURI->$dottyGithubRawUserContentUrl/$dottyVersion/")
         } else {
           Nil
         }