fix: spread parserOpts and writerOpts to avoid immutable object error

The preset config objects may be frozen. Create shallow copies before
passing to conventional-changelog-core to avoid "Cannot modify
immutable object" error.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: sarahdayan

packages/shipjs/src/step/prepare/updateChangelog.js

@@ -169,8 +169,8 @@ function runConventionalChangelog({
     args,
     templateContext,
     { ...gitRawCommitsOpts, path: dir },
-    parserOpts,
-    writerOpts,
+    parserOpts ? { ...parserOpts } : undefined,
+    writerOpts ? { ...writerOpts } : undefined,
     { path: dir, cwd: dir }
   ).on('error', reject);