[Analysis API] Simplify 'getNotUnderContentRootModule()'

In the resulting implementation of dangling file modules,
'getNotUnderContentRootModule()' is never called with a not-null file.

analysis/analysis-api-standalone/src/org/jetbrains/kotlin/analysis/project/structure/impl/KtStandaloneProjectStructureProvider.kt

@@ -7,16 +7,13 @@ package org.jetbrains.kotlin.analysis.project.structure.impl
 
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
-import com.intellij.psi.PsiFile
 import com.intellij.psi.PsiFileSystemItem
 import com.intellij.psi.PsiJavaFile
-import com.intellij.util.containers.ContainerUtil
 import org.jetbrains.kotlin.analysis.api.standalone.base.project.structure.KtStaticProjectStructureProvider
 import org.jetbrains.kotlin.analysis.api.standalone.base.project.structure.StandaloneProjectFactory.findJvmRootsForJavaFiles
 import org.jetbrains.kotlin.analysis.low.level.api.fir.project.structure.LLFirBuiltinsSessionFactory
 import org.jetbrains.kotlin.analysis.project.structure.*
 import org.jetbrains.kotlin.platform.TargetPlatform
-import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.serialization.deserialization.builtins.BuiltInSerializerProtocol
 import org.jetbrains.kotlin.utils.KotlinExceptionWithAttachments
 
@@ -33,25 +30,12 @@ internal class KtStandaloneProjectStructureProvider(
         )
     }
 
-    private val notUnderContentRootModuleCache = ContainerUtil.createConcurrentWeakMap<PsiFile, KtNotUnderContentRootModule>()
-
     private val builtinsModule: KtBuiltinsModule by lazy {
         LLFirBuiltinsSessionFactory.getInstance(project).getBuiltinsSession(platform).ktModule as KtBuiltinsModule
     }
 
-    override fun getNotUnderContentRootModule(project: Project, file: PsiFile?): KtNotUnderContentRootModule {
+    override fun getNotUnderContentRootModule(project: Project): KtNotUnderContentRootModule {
-        if (file == null) {
+        return ktNotUnderContentRootModuleWithoutPsiFile
-            return ktNotUnderContentRootModuleWithoutPsiFile
-        }
-
-        return notUnderContentRootModuleCache.getOrPut(file) {
-            KtNotUnderContentRootModuleImpl(
-                name = file.name,
-                moduleDescription = "Standalone-not-under-content-root-module-for-$file",
-                file = file,
-                project = project,
-            )
-        }
     }
 
     @OptIn(KtModuleStructureInternals::class)

analysis/analysis-test-framework/tests/org/jetbrains/kotlin/analysis/test/framework/services/KtTestProjectStructureProvider.kt

@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.analysis.test.framework.services
 
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
-import com.intellij.psi.PsiFile
 import com.intellij.psi.PsiFileSystemItem
 import org.jetbrains.kotlin.analysis.api.standalone.base.project.structure.KtModuleProjectStructure
 import org.jetbrains.kotlin.analysis.api.standalone.base.project.structure.KtStaticProjectStructureProvider
@@ -22,7 +21,7 @@ class KtTestProjectStructureProvider(
     private val builtinsModule: KtBuiltinsModule,
     private val projectStructure: KtModuleProjectStructure,
 ) : KtStaticProjectStructureProvider() {
-    override fun getNotUnderContentRootModule(project: Project, file: PsiFile?): KtNotUnderContentRootModule {
+    override fun getNotUnderContentRootModule(project: Project): KtNotUnderContentRootModule {
         error("Not-under content root modules most be initialized explicitly in tests")
     }
 

analysis/project-structure/src/org/jetbrains/kotlin/analysis/project/structure/ProjectStructureProvider.kt

@@ -42,7 +42,7 @@ public abstract class ProjectStructureProvider {
      */
     public abstract fun getModule(element: PsiElement, contextualModule: KtModule?): KtModule
 
-    protected abstract fun getNotUnderContentRootModule(project: Project, file: PsiFile?): KtNotUnderContentRootModule
+    protected abstract fun getNotUnderContentRootModule(project: Project): KtNotUnderContentRootModule
 
     @OptIn(KtModuleStructureInternals::class)
     protected fun computeSpecialModule(file: PsiFile): KtModule? {
@@ -81,7 +81,7 @@ public abstract class ProjectStructureProvider {
             return getModule(contextElement, contextualModule = null)
         }
 
-        return getNotUnderContentRootModule(file.project, file = null)
+        return getNotUnderContentRootModule(file.project)
     }
 
     /**