revert back to previous asm toolchain for CI

TDHolmes · TDHolmes · commit a3ee69a81047 · 2021-12-15T11:56:57.000-08:00
diff --git a/asm-toolchain b/asm-toolchain
@@ -1 +1 @@
-nightly-2021-08-26
+nightly-2020-08-26
