bump attr.s requirement

Author: richvdh

synapse/python_dependencies.py

@@ -75,11 +75,9 @@
     "phonenumbers>=8.2.0",
     # we use GaugeHistogramMetric, which was added in prom-client 0.4.0.
     "prometheus_client>=0.4.0",
-    # we use attr.validators.deep_iterable, which arrived in 19.1.0 (Note:
-    # Fedora 31 only has 19.1, so if we want to upgrade we should wait until 33
-    # is out in November.)
+    # we use `order`, which arrived in attrs 19.2.0.
     # Note: 21.1.0 broke `/sync`, see #9936
-    "attrs>=19.1.0,!=21.1.0",
+    "attrs>=19.2.0,!=21.1.0",
     "netaddr>=0.7.18",
     "Jinja2>=2.9",
     "bleach>=1.4.3",