tests: Add mechanism to avoid using extractors that we are not testing

tests/fixtures.py

@@ -7,4 +7,19 @@ import pytest
 def process(tmp_path):
     os.chdir(tmp_path)
     process = subprocess.run(['archivebox', 'init'], capture_output=True)
-    return process
+    return process
+
+@pytest.fixture
+def disable_extractors_dict():
+    env = os.environ.copy()
+    env.update({
+        "USE_WGET": "false",
+        "USE_SINGLEFILE": "false",
+        "SAVE_PDF": "false",
+        "SAVE_SCREENSHOT": "false",
+        "SAVE_DOM": "false",
+        "USE_GIT": "false",
+        "SAVE_MEDIA": "false",
+        "SAVE_ARCHIVE_DOT_ORG": "false"
+    })
+    return env