chore: checkpoint before Python removal

vendor/crossbeam-utils/build-common.rs

@@ -0,0 +1,13 @@
+// The target triplets have the form of 'arch-vendor-system'.
+//
+// When building for Linux (e.g. the 'system' part is
+// 'linux-something'), replace the vendor with 'unknown'
+// so that mapping to rust standard targets happens correctly.
+fn convert_custom_linux_target(target: String) -> String {
+    let mut parts: Vec<&str> = target.split('-').collect();
+    let system = parts.get(2);
+    if system == Some(&"linux") {
+        parts[1] = "unknown";
+    };
+    parts.join("-")
+}