ci(codspeed): skip update-partial owner-drift gate under simulation

CodSpeed's simulation runner disposes the bench's owner subtree before
afterAll runs (final=1 vs baseline=4006), so the strict drift gate
fires even though no real leak occurred. Other benches use a tolerant
`> 5` check that happens to ignore this disposal artifact; keeping the
strict gate but env-guarding it preserves the local-dev contract.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ryansolid

packages/solid-web/test/update-partial.bench.tsx

@@ -80,7 +80,9 @@ bench("update-partial: 100/1000 rows × 16 iterations", () => {
 afterAll(() => {
   const finalOwners = ownerTotal(rootOwner);
   for (const dispose of cleanups) dispose();
-  if (finalOwners !== baselineOwners) {
+  // CodSpeed simulation mode disposes the bench's owner subtree before
+  // afterAll fires, so the strict drift gate only runs in the local dev path.
+  if (!process.env.CODSPEED_RUNNER_MODE && finalOwners !== baselineOwners) {
     throw new Error(
       `Owner-tree drift on update path: baseline=${baselineOwners}, final=${finalOwners}`
     );