fix: add aarch64-musl target config for cross-compilation support

Author: futhr

native/ex_maude_nif/.cargo/config.toml

@@ -5,9 +5,10 @@ rustflags = [
 ]
 
 [target.x86_64-unknown-linux-musl]
-rustflags = [
-  "-C", "target-feature=-crt-static"
-]
+rustflags = ["-C", "target-feature=-crt-static"]
+
+[target.aarch64-unknown-linux-musl]
+rustflags = ["-C", "target-feature=-crt-static"]
 
 [profile.release]
 lto = true