[llvm] [Github] Bump CI containers to LLVM 23.1.1 (PR #223775)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/223775

This means we no longer have -Wunused-template enabled by default, for which the LLVM tree is still not clean.

>From 13bad0fce582b6aaf7ce249cad4507f77a1a32de Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Tue, 15 Sep 2026 18:10:22 +0000
Subject: [PATCH] [Github] Bump CI containers to LLVM 23.1.1

This means we no longer have -Wunused-template enabled by default, for
which the LLVM tree is still not clean.
---
 .../workflows/containers/github-action-ci-windows/Dockerfile    | 2 +-
 .github/workflows/containers/github-action-ci/Dockerfile        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/containers/github-action-ci-windows/Dockerfile b/.github/workflows/containers/github-action-ci-windows/Dockerfile
index 5f1a5887a6435..e517ea481b9e6 100644
--- a/.github/workflows/containers/github-action-ci-windows/Dockerfile
+++ b/.github/workflows/containers/github-action-ci-windows/Dockerfile
@@ -110,7 +110,7 @@ RUN powershell -Command \
     rm actions-runner-win.zip
 
 # Set the LLVM_VERSION environment variable
-ENV LLVM_VERSION=23.1.0
+ENV LLVM_VERSION=23.1.1
 
 # Download and extract Clang compiler.
 # Create directories, download, extract, and clean up all in one layer
diff --git a/.github/workflows/containers/github-action-ci/Dockerfile b/.github/workflows/containers/github-action-ci/Dockerfile
index 6028f168b1bf7..534a1f03a83b7 100644
--- a/.github/workflows/containers/github-action-ci/Dockerfile
+++ b/.github/workflows/containers/github-action-ci/Dockerfile
@@ -2,7 +2,7 @@ FROM docker.io/library/ubuntu:24.04 AS base
 ENV LLVM_SYSROOT=/opt/llvm
 
 FROM base AS stage1-toolchain
-ENV LLVM_VERSION=23.1.0
+ENV LLVM_VERSION=23.1.1
 
 RUN apt-get update && \
     apt-get install -y \