fix: scale databases worker to handle parallel test load

The root cause of flaky attribute processing tests is that a single
appwrite-worker-databases container cannot keep up with attribute
creation jobs when tests run in parallel via paratest.

This fix:
- Scales the databases worker to 4 instances during E2E service tests
- Reverts timeout increases that masked the underlying issue

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/tests.yml

@@ -201,7 +201,7 @@ jobs:
         run: |
           docker load --input /tmp/${{ env.IMAGE }}.tar
           sed -i 's|^_APP_BROWSER_HOST=.*|_APP_BROWSER_HOST=http://invalid-browser/v1|' .env
-          docker compose up -d
+          docker compose up -d --scale appwrite-worker-databases=4
           sleep 30
 
       - name: Wait for Open Runtimes
@@ -284,7 +284,7 @@ jobs:
       - name: Load and Start Appwrite
         run: |
           docker load --input /tmp/${{ env.IMAGE }}.tar
-          docker compose up -d
+          docker compose up -d --scale appwrite-worker-databases=4
           sleep 30
 
       - name: Wait for Open Runtimes