Set missingOk if sbtClassifiers is true

Seems sbt doesn't do it by default

modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/ArtifactsTasks.scala

@@ -72,6 +72,7 @@ object ArtifactsTasks {
           .withFollowHttpToHttpsRedirections(true),
         parallel = parallelDownloads,
         classpathOrder = true,
+        missingOk = sbtClassifiers
       )
 
       val resOrError = ArtifactsRun.artifacts(

modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/UpdateTasks.scala

@@ -139,6 +139,7 @@ object UpdateTasks {
               includeSignatures,
               sbtBootJarOverrides,
               classpathOrder = true,
+              missingOk = sbtClassifiers
             )
 
             val rep = UpdateRun.update(params, verbosityLevel, log)

modules/sbt-lm-coursier/src/main/scala/coursier/sbtlmcoursier/LmCoursierPlugin.scala

@@ -160,7 +160,8 @@ object LmCoursierPlugin extends AutoPlugin {
           .withIvyHome(ivyPaths.value.ivyHome)
           .withStrict(strict)
           .withForceVersions(userForceVersions.toVector)
-          .withMissingOk(updateConfig.missingOk)
+          // seems missingOk is false in the updateConfig of updateSbtClassifiers?
+          .withMissingOk(updateConfig.missingOk || sbtClassifiers)
           .withSbtClassifiers(sbtClassifiers)
       }
     }