Fix CI.

Author: Dirbaio

embedded-hal-nb/Cargo.toml

@@ -16,5 +16,5 @@ embedded-hal = { version = "=1.0.0-alpha.9", path = "../embedded-hal" }
 nb = "1"
 
 [dev-dependencies]
-cortex-m-rt = "=0.7.1"  # 0.7.2 bumped its MSRV higher than embedded-hal's
+cortex-m-rt = "0.7"
 stm32f1 = { version = "0.15", features = ["stm32f103", "rt"] }