fix(plugin-cloud-storage): missing 'prefix' in cloud storage plugin (#11970)

## Fix
We were able to narrow it down to this call
816fb28f55/packages/plugin-cloud-storage/src/utilities/getFilePrefix.ts (L26-L41)

Adding `draft: true` fixes the issue. It seems that the `prefix` can
only be found in a draft, and without `draft: true` those drafts aren't
searched.

### Issue reproduction

In the community folder, enable versioning for the media collection and
install the `s3storage` plugin (see Git patch). I use `minio` to have a
local S3 compatible backend and then I run the app with:
`AWS_ACCESS_KEY_ID=minioadmin AWS_SECRET_ACCESS_KEY=minioadmin
START_MEMORY_DB=true pnpm dev _community`.

Next, open the media collection and create a new entry. Then open that
entry, remove the file it currently has, and upload a new file. Save as
draft.

Now the media can no longer be accessed and the thumbnails are broken.

If you make an edit but save it by publishing the issue goes away. I
also couldn't reproduce this by adding a text field, changing that, and
saving the document as draft.

```diff
diff --git test/_community/collections/Media/index.ts test/_community/collections/Media/index.ts
index bb5edd0349..689423053c 100644
--- test/_community/collections/Media/index.ts
+++ test/_community/collections/Media/index.ts
@@ -9,6 +9,9 @@ export const MediaCollection: CollectionConfig = {
     read: () => true,
   },
   fields: [],
+  versions: {
+    drafts: true,
+  },
   upload: {
     crop: true,
     focalPoint: true,
diff --git test/_community/config.ts test/_community/config.ts
index ee1aee6e46..c81ec5f933 100644
--- test/_community/config.ts
+++ test/_community/config.ts
@@ -7,6 +7,7 @@ import { devUser } from '../credentials.js'
 import { MediaCollection } from './collections/Media/index.js'
 import { PostsCollection, postsSlug } from './collections/Posts/index.js'
 import { MenuGlobal } from './globals/Menu/index.js'
+import { s3Storage } from '@payloadcms/storage-s3'
 
 const filename = fileURLToPath(import.meta.url)
 const dirname = path.dirname(filename)
@@ -24,6 +25,21 @@ export default buildConfigWithDefaults({
     // ...add more globals here
     MenuGlobal,
   ],
+  plugins: [
+    s3Storage({
+      enabled: true,
+      bucket: 'amboss',
+      config: {
+        region: 'eu-west-1',
+        endpoint: 'http://localhost:9000',
+      },
+      collections: {
+        media: {
+          prefix: 'media',
+        },
+      },
+    }),
+  ],
   onInit: async (payload) => {
     await payload.create({
       collection: 'users',

```

## Screen recording

https://github.com/user-attachments/assets/b13be4a3-e858-427a-8bfa-6592b87748ee

packages/plugin-cloud-storage/src/utilities/getFilePrefix.ts

@@ -26,6 +26,7 @@ export async function getFilePrefix({
   const files = await req.payload.find({
     collection: collection.slug,
     depth: 0,
+    draft: true,
     limit: 1,
     pagination: false,
     where: {