fix(ci): update snapshots after CDK version sync in release workflow (#848)

The release workflow syncs @aws/agentcore-cdk to the latest npm version
but did not update the asset snapshot tests, causing the test-and-build
job to fail with a snapshot mismatch.

Author: jesseturner21

.github/workflows/release.yml

@@ -134,6 +134,11 @@ jobs:
           echo "branch=release/v$NEW_VERSION" >> $GITHUB_OUTPUT
           echo "New version: $NEW_VERSION"
 
+      - name: Update snapshots after CDK sync
+        run: |
+          npm run test:update-snapshots
+          echo "✓ Snapshots updated"
+
       - name: Regenerate JSON schema
         run: |
           npm run build