fix: use correct Bun flags and pin version

- Change --frozen-lockfile to --frozen (correct for Bun)
- Pin Bun version to 1.1.38 instead of latest for consistency
- Addresses feedback from Graphite and Ellipsis bots

Co-Authored-By: [email protected] <[email protected]>

Author: devin-ai-integration[bot]

.github/workflows/test.yml

@@ -15,10 +15,10 @@ jobs:
 
       - uses: oven-sh/setup-bun@v1
         with:
-          bun-version: latest
+          bun-version: 1.1.38
 
       - name: Install dependencies
-        run: bun install --frozen-lockfile
+        run: bun install --frozen
 
       - name: Run tests
         run: bun test