[213] Do not remove deprecated ExtensionsArea.registerExtensionPoint

The method is proved to be used in klint project
https://github.com/pinterest/ktlint/blob/c5a81e0d4198fa5cb2cac69967080e01e365b837/ktlint-rule-engine/src/main/kotlin/com/pinterest/ktlint/rule/engine/internal/KotlinPsiFileFactory.kt#L121

There is an issue about the remove: pinterest/ktlint#1981

KTI-1114

prepare/compiler/compiler.pro

@@ -259,6 +259,12 @@
     public void registerExtension(...);
 }
 
+# Temporary for klint https://github.com/pinterest/ktlint/blob/c5a81e0d4198fa5cb2cac69967080e01e365b837/ktlint-rule-engine/src/main/kotlin/com/pinterest/ktlint/rule/engine/internal/KotlinPsiFileFactory.kt#L121
+# Should be removed after after 26.04.2024
+-keepclassmembers class com.intellij.openapi.extensions.ExtensionsArea {
+    public void registerExtensionPoint(java.lang.String, java.lang.String, com.intellij.openapi.extensions.ExtensionPoint.Kind);
+}
+
 # Serialization plugin
 
 -keep class com.intellij.openapi.util.io.JarUtil {