drop obsolesce annotation from runReadAction (it forces to use pre-kotlin API inside blocking context)

GitOrigin-RevId: ba12f14d8eda7f418ff60e32ae1509b8615610e6

platform/core-api/src/com/intellij/openapi/application/actions.kt

@@ -23,7 +23,6 @@ fun <T> runUndoTransparentWriteAction(runnable: () -> T): T {
 /**
  * Use [readAction].
  */
-@Obsolete
 fun <T> runReadAction(runnable: () -> T): T {
   return ApplicationManager.getApplication().runReadAction(Computable(runnable))
 }