[tests] run file_tests with pywikibot-oauth

pywikibot-oauth is a registered account on commons-beta.
Run tests there.

Change-Id: I3f186c3388185ce83a34c831391319a00a5e45f2

.github/workflows/oauth_tests-ci.yml

@@ -100,9 +100,10 @@ jobs:
       env:
         PYWIKIBOT_TEST_WRITE: ${{ matrix.domain == 'test.wikipedia.org' && 1 || 0}}
         PYWIKIBOT_TEST_OAUTH: ${{ secrets[format('{0}', steps.token.outputs.uppercase)] }}
+        PYWIKIBOT_TEST_MODULES=file,oauth
       run: |
         python pwb.py version
-        coverage run -m unittest -vv tests/oauth_tests.py
+        coverage run -m unittest -vv
 
     - name: Show coverage statistics
       run: |