ci: drop stale 'working-directory: predomicsapp' from E2E steps

The three E2E steps had working-directory: predomicsapp, which
resolved to /home/runner/work/predomicsapp/predomicsapp/predomicsapp
(a non-existent nested dir) since the repo itself is checked out at
/home/runner/work/predomicsapp/predomicsapp.

package.json, package-lock.json and playwright.config.mjs live at the
repo root, so the steps should just run there with no working-directory
override.

Author: eprifti

.github/workflows/ci.yml

@@ -123,11 +123,9 @@ jobs:
           node-version: "20"
 
       - name: Install E2E dependencies
-        working-directory: predomicsapp
         run: npm ci
 
       - name: Install Playwright browser
-        working-directory: predomicsapp
         run: npx playwright install chromium
 
       - name: Start app for E2E
@@ -159,7 +157,6 @@ jobs:
           done
 
       - name: Run E2E tests
-        working-directory: predomicsapp
         run: npm run test:e2e
         env:
           BASE_URL: http://localhost:8001