test(uploads): give the presigner credentials where the client now reads them

The S3 client resolves credentials through the SDK default chain, which reads
process.env, so the presigner test stubs the keys there instead of the env
module mock.

Author: waleedlatif1

apps/sim/lib/uploads/providers/s3/presigned-upload.test.ts

@@ -4,17 +4,13 @@
  * missing from `headers`, or a metadata key both signed as a header and hoisted
  * into the query, makes the provider reject or strip the upload.
  */
-import { resetEnvMock, setEnv } from '@sim/testing/mocks/env.mock'
 import { setUploadsConfig, uploadsConfigMock } from '@sim/testing/mocks/uploads-config.mock'
-import { afterAll, beforeEach, describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 vi.mock('@/lib/uploads/config', () => uploadsConfigMock)
 
 import { getS3PresignedUploadUrl, resetS3ClientForTesting } from '@/lib/uploads/providers/s3/client'
 
-setEnv({ AWS_ACCESS_KEY_ID: 'test-access-key', AWS_SECRET_ACCESS_KEY: 'test-secret-key' })
-afterAll(resetEnvMock)
-
 /** Headers the browser sets itself and the uploader never supplies. */
 const TRANSPORT_HEADERS = new Set(['host', 'content-length'])
 
@@ -44,7 +40,12 @@ async function presign() {
 }
 
 describe('getS3PresignedUploadUrl', () => {
-  beforeEach(() => configure(undefined))
+  beforeEach(() => {
+    // The client resolves credentials through the SDK's default chain, which reads process.env.
+    vi.stubEnv('AWS_ACCESS_KEY_ID', 'test-access-key')
+    vi.stubEnv('AWS_SECRET_ACCESS_KEY', 'test-secret-key')
+    configure(undefined)
+  })
 
   it('signs metadata as uploader-sent headers for a custom S3-compatible endpoint', async () => {
     configure('https://s3.de.io.cloud.ovh.net')