Prepare for merging from rust-lang/rust

The rustc-josh-sync Cronjob Bot · The rustc-josh-sync Cronjob Bot · commit 8d82365a64d8 · 2025-07-28T04:18:33.000Z
This updates the rust-version file to 2b5e239.
diff --git a/src/doc/rustc-dev-guide/rust-version b/src/doc/rustc-dev-guide/rust-version
@@ -1 +1 @@
-efd420c770bb179537c01063e98cb6990c439654
+2b5e239c6b86cde974b0ef0f8e23754fb08ff3c5
