fix(test): use assert_ne macro for clarity

Replaced a manual inequality assertion with the dedicated `assert_ne!` macro in a regression test. This makes the test's intent clearer and follows standard Rust testing conventions.

Auto-committed-on: dragonfly
Co-authored-by: Medulla <medulla@tinyhumans.ai>

Author: senamakel

crates/tinytools-agent/src/parse/test/regressions.rs

@@ -127,6 +127,6 @@ fn markdown_fence_with_a_json_body_parses() {
     let (text, calls) = parse(input);
     assert_eq!(calls.len(), 1);
     assert_eq!(calls[0].name, "ping");
-    assert!(calls[0].source != CallSource::Native);
+    assert_ne!(calls[0].source, CallSource::Native);
     assert!(text.contains("preamble") && text.contains("postamble"));
 }