test(calculate-version): 補上 release JSON 解析失敗路徑測試

新增 fetchReleases 收到無法解析 JSON 時拋出「回傳資料無法解析」的測試案例。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/releases.test.js

@@ -65,6 +65,18 @@ test('fetchReleases 對非 2xx 回應拋錯', async () => {
     );
 });
 
+test('fetchReleases 對無法解析的 JSON 回應拋錯', async () => {
+    await withFetch(
+        async () => jsonResponse('{ this is not valid json', true),
+        async () => {
+            await assert.rejects(
+                () => fetchReleases('https://gitea.example.com/api'),
+                /回傳資料無法解析/,
+            );
+        },
+    );
+});
+
 test('fetchReleases 對非陣列回應拋錯', async () => {
     await withFetch(
         async () => jsonResponse({ message: 'oops' }),