chore: add thumbv6m-none-eabi target for no_std CI check

Author: kvinwang

rust-toolchain.toml

@@ -5,4 +5,4 @@
 [toolchain]
 channel = "1.92"
 components = ["rustfmt", "clippy", "rust-analyzer"]
-targets = ["wasm32-unknown-unknown", "x86_64-unknown-linux-musl"]
+targets = ["wasm32-unknown-unknown", "x86_64-unknown-linux-musl", "thumbv6m-none-eabi"]