IJPL-162718 do not load an extension list in read action

(cherry picked from commit de96ad6082f723d14a661b80b0c98b023e384ef9)

IJ-CR-147194

GitOrigin-RevId: 48942b3426105cb29e74f22c29659d9a1381908c

platform/projectModel-impl/src/com/intellij/workspaceModel/core/fileIndex/impl/WorkspaceFileIndexImpl.kt

@@ -226,8 +226,11 @@ class WorkspaceFileIndexImpl(private val project: Project) : WorkspaceFileIndexE
   }
 
   override suspend fun initialize() {
-    readAction {
-      initializeBlocking()
+    if (indexData is EmptyWorkspaceFileIndexData) {
+      val contributors = EP_NAME.extensionList
+      readAction {
+        indexData = WorkspaceFileIndexDataImpl(contributorList = contributors, project = project, parentDisposable = this)
+      }
     }
   }