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

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

src/ext/rust

@@ -1 +1 @@
-Subproject commit 40759064756f668c25ad1347faa793fc0d6afe8b
+Subproject commit a870933f6b20fc9c47a13e9d980d56b49e30ddb5