fix(db-mongodb): localized dates being returned as date objects instead of strings (#12354)

Fixes https://github.com/payloadcms/payload/issues/12334

We weren't passing locale through to the Date transformer function so
localized dates were being read as objects instead of strings.

test/localization/int.spec.ts

@@ -27,6 +27,7 @@ import {
   defaultLocale as englishLocale,
   englishTitle,
   hungarianLocale,
+  localizedDateFieldsSlug,
   localizedPostsSlug,
   localizedSortSlug,
   portugueseLocale,
@@ -431,6 +432,32 @@ describe('Localization', () => {
       })
     })
 
+    describe('Localized date', () => {
+      it('can create a localized date', async () => {
+        const document = await payload.create({
+          collection: localizedDateFieldsSlug,
+          data: {
+            localizedDate: new Date().toISOString(),
+            date: new Date().toISOString(),
+          },
+        })
+        expect(document.localizedDate).toBeTruthy()
+      })
+
+      it('data is typed as string', async () => {
+        const document = await payload.create({
+          collection: localizedDateFieldsSlug,
+          data: {
+            localizedDate: new Date().toISOString(),
+            date: new Date().toISOString(),
+          },
+        })
+
+        expect(typeof document.localizedDate).toBe('string')
+        expect(typeof document.date).toBe('string')
+      })
+    })
+
     describe('Localized Sort Count', () => {
       const expectedTotalDocs = 5
       const posts: LocalizedSort[] = []