swh-indexer: update to 2.9.1

Ref. infra/sysadm-environment#4682

apps/swh-indexer/requirements-frozen.txt

@@ -3,12 +3,10 @@ aiohttp-utils==3.1.1
 aiosignal==1.3.1
 amqp==5.1.1
 async-timeout==4.0.2
-asynctest==0.13.0
 attrs==22.1.0
 attrs-strict==1.0.0
 billiard==3.6.4.0
 blinker==1.5
-cached-property==1.5.2
 cachetools==5.2.0
 cassandra-driver==3.25.0
 celery==5.2.7
@@ -28,7 +26,7 @@ frozenlist==1.3.3
 geomet==0.2.1.post1
 gunicorn==20.1.0
 humanize==4.4.0
-hypothesis==6.58.1
+hypothesis==6.58.2
 idna==3.4
 importlib-metadata==4.13.0
 iniconfig==1.1.1
@@ -68,7 +66,7 @@ six==1.16.0
 sortedcontainers==2.4.0
 swh.core==2.17.0
 swh.counters==0.9.1
-swh.indexer==2.9.0
+swh.indexer==2.9.1
 swh.journal==1.2.1
 swh.model==6.6.0
 swh.objstorage==2.0.1