Automated update to Github CI to rustc nightly-2025-08-19

Update Nightly Rustc Bot · Update Nightly Rustc Bot · commit 38ba6cd9351b · 2025-08-21T00:34:02.000Z
diff --git a/nightly-version b/nightly-version
@@ -1 +1 @@
-nightly-2025-08-09
+nightly-2025-08-19
