Use edition 2021 for xtask.

reitermarkus · reitermarkus · commit 87d8b04d778e · 2022-05-05T15:06:52.000+02:00
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
@@ -2,7 +2,7 @@
 name = "xtask"
 version = "0.0.0"
 authors = ["The Cortex-M Team <cortex-m@teams.rust-embedded.org>"]
-edition = "2018"
+edition = "2021"
 publish = false
 
 [[test]]
