Bump io to 1.3.0-M3

I had to turn off -Xfatal-warnings in commandProj because after updating
io, commandProj depends on the deprecated EventMonitor class. In #4335,
I stop using EventMonitor, but deprecate the Watched class which is both
defined and used (as an unused attribute key) in commandProj. I think we
can probably get rid of Watched in 1.4.x and certainly in a hypothetical
2.x, so hopefully we can restore -Xfatal-warnings sooner than later.

I also had to replace uses of IO.classLocationFile with
IO.classLocationPath to avoid compilation failures due to
-Xfatal-warnings.

build.sbt

@@ -459,6 +459,8 @@ lazy val commandProj = (project in file("main-command"))
     name := "Command",
     libraryDependencies ++= Seq(launcherInterface, sjsonNewScalaJson.value, templateResolverApi),
     Compile / scalacOptions += "-Ywarn-unused:-locals,-explicits,-privates",
+    // Removing -Xfatal-warnings is necessary because BasicKeys contains a Key for a deprecated class.
+    Compile / scalacOptions -= "-Xfatal-warnings",
     managedSourceDirectories in Compile +=
       baseDirectory.value / "src" / "main" / "contraband-scala",
     sourceManaged in (Compile, generateContrabands) := baseDirectory.value / "src" / "main" / "contraband-scala",

main-actions/src/main/scala/sbt/ForkTests.scala

@@ -125,8 +125,8 @@ private[sbt] object ForkTests {
         acceptorThread.start()
 
         val fullCp = classpath ++: Seq(
-          IO.classLocationFile[ForkMain],
-          IO.classLocationFile[Framework]
+          IO.classLocationPath[ForkMain].toFile,
+          IO.classLocationPath[Framework].toFile
         )
         val options = Seq(
           "-classpath",

main-actions/src/main/scala/sbt/compiler/Eval.scala

@@ -69,7 +69,7 @@ final class Eval(
     backing: Option[File]
 ) {
   def this(mkReporter: Settings => Reporter, backing: Option[File]) =
-    this(Nil, IO.classLocationFile[Product] :: Nil, mkReporter, backing)
+    this(Nil, IO.classLocationPath[Product].toFile :: Nil, mkReporter, backing)
   def this() = this(s => new ConsoleReporter(s), None)
 
   backing.foreach(IO.createDirectory)

main/src/main/scala/sbt/internal/parser/SbtParser.scala

@@ -42,7 +42,7 @@ private[sbt] object SbtParser {
     """.stripMargin
 
   private final val defaultClasspath =
-    sbt.io.Path.makeString(sbt.io.IO.classLocationFile[Product] :: Nil)
+    sbt.io.Path.makeString(sbt.io.IO.classLocationPath[Product].toFile :: Nil)
 
   /**
    * Provides the previous error reporting functionality in

project/Dependencies.scala

@@ -9,7 +9,7 @@ object Dependencies {
   val baseScalaVersion = scala212
 
   // sbt modules
-  private val ioVersion = "1.2.1"
+  private val ioVersion = "1.3.0-M3"
   private val utilVersion = "1.3.0-M2"
   private val lmVersion = "1.2.1"
   private val zincVersion = "1.2.2"

run/src/test/scala/sbt/ForkTest.scala

@@ -31,8 +31,8 @@ object ForkTest extends Properties("Fork") {
   lazy val genRelClasspath = nonEmptyListOf(path)
 
   lazy val requiredEntries =
-    IO.classLocationFile[scala.Option[_]] ::
-      IO.classLocationFile[sbt.exit.type] ::
+    IO.classLocationPath[scala.Option[_]].toFile ::
+      IO.classLocationPath[sbt.exit.type].toFile ::
       Nil
   lazy val mainAndArgs =
     "sbt.exit" ::

testing/src/main/scala/sbt/TestFramework.scala

@@ -250,7 +250,7 @@ object TestFramework {
       scalaInstance: ScalaInstance,
       tempDir: File
   ): ClassLoader = {
-    val interfaceJar = IO.classLocationFile(classOf[testing.Framework])
+    val interfaceJar = IO.classLocationPath(classOf[testing.Framework]).toFile
     val interfaceFilter = (name: String) =>
       name.startsWith("org.scalatools.testing.") || name.startsWith("sbt.testing.")
     val notInterfaceFilter = (name: String) => !interfaceFilter(name)