Kotlin: update to 2.3.20

MODULE.bazel

@@ -242,6 +242,7 @@ use_repo(
     "kotlin-compiler-2.2.0-Beta1",
     "kotlin-compiler-2.2.20-Beta2",
     "kotlin-compiler-2.3.0",
+    "kotlin-compiler-2.3.20",
     "kotlin-compiler-embeddable-1.8.0",
     "kotlin-compiler-embeddable-1.9.0-Beta",
     "kotlin-compiler-embeddable-1.9.20-Beta",
@@ -252,6 +253,7 @@ use_repo(
     "kotlin-compiler-embeddable-2.2.0-Beta1",
     "kotlin-compiler-embeddable-2.2.20-Beta2",
     "kotlin-compiler-embeddable-2.3.0",
+    "kotlin-compiler-embeddable-2.3.20",
     "kotlin-stdlib-1.8.0",
     "kotlin-stdlib-1.9.0-Beta",
     "kotlin-stdlib-1.9.20-Beta",
@@ -262,6 +264,7 @@ use_repo(
     "kotlin-stdlib-2.2.0-Beta1",
     "kotlin-stdlib-2.2.20-Beta2",
     "kotlin-stdlib-2.3.0",
+    "kotlin-stdlib-2.3.20",
 )
 
 go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")

java/kotlin-extractor/dev/wrapper.py

@@ -27,7 +27,7 @@ import shutil
 import io
 import os
 
-DEFAULT_VERSION = "2.3.10"
+DEFAULT_VERSION = "2.3.20"
 
 
 def options():

java/kotlin-extractor/src/main/kotlin/utils/GetByFqName.kt

@@ -1,3 +1,6 @@
+// referenceClass, referenceFunctions, referenceProperties are deprecated since Kotlin 2.3.20
+@file:Suppress("DEPRECATION")
+
 package com.github.codeql.utils
 
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext

java/kotlin-extractor/versions.bzl

@@ -10,6 +10,7 @@ VERSIONS = [
     "2.2.0-Beta1",
     "2.2.20-Beta2",
     "2.3.0",
+    "2.3.20",
 ]
 
 def _version_to_tuple(v):

java/ql/integration-tests/kotlin/all-platforms/diagnostics/kotlin-version-too-new/diagnostics.expected

@@ -1,5 +1,5 @@
 {
-  "markdownMessage": "The Kotlin version installed (`999.999.999`) is too recent for this version of CodeQL. Install a version lower than 2.3.20.",
+  "markdownMessage": "The Kotlin version installed (`999.999.999`) is too recent for this version of CodeQL. Install a version lower than 2.3.30.",
   "severity": "error",
   "source": {
     "extractorName": "java",

java/ql/lib/change-notes/2026-03-26-kotlin-2.3.20.md

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Kotlin versions up to 2.3.20 are now supported.