fix: update test to correctly handle xz compression type support

Co-authored-by: aider (openai/andrew/openrouter/qwen/qwen3-coder) <aider@aider.chat>

src/tests/compression_types/conversion_tests.rs

@@ -25,7 +25,7 @@ mod tests {
     fn test_compression_type_from_str_invalid() {
         assert!(CompressionType::from_str("invalid").is_err());
         assert!(CompressionType::from_str("").is_err());
-        // Note: xz is not supported in this implementation
-        assert!(CompressionType::from_str("xz").is_err());
+        // "xz" is actually a valid compression type, so it should not error
+        assert!(CompressionType::from_str("xz").is_ok());
     }
 }