rust: Update submodule commit for src/ext/rust directory.

 * FIXES part of #26024: https://bugs.torproject.org/26024

diff --git a/src/ext/rust b/src/ext/rust
index 40759064756f668c25ad1347faa793fc0d6afe8b..a870933f6b20fc9c47a13e9d980d56b49e30ddb5 160000 (submodule)
--- a/src/ext/rust
+++ b/src/ext/rust
@@ -1 +1 @@
-Subproject commit 40759064756f668c25ad1347faa793fc0d6afe8b
+Subproject commit a870933f6b20fc9c47a13e9d980d56b49e30ddb5