Automated update to Github CI to rustc nightly-2025-08-20

Update Nightly Rustc Bot · Update Nightly Rustc Bot · commit acfe00924111 · 2025-08-21T02:04:40.000Z
diff --git a/nightly-version b/nightly-version
@@ -1 +1 @@
-nightly-2024-08-04
+nightly-2025-08-20
