Fix pyyaml version (open-telemetry#1892)

Author: ocelotl

tox.ini

@@ -502,7 +502,7 @@ commands =
   codespell
 
 [testenv:lint]
-basepython: python3.10
+basepython: python3.9
 recreate = False
 deps =
   -c dev-requirements.txt
@@ -596,6 +596,7 @@ deps =
   flaky==3.7.0
   remoulade>=0.50
   mysqlclient~=2.1.1
+  pyyaml==5.3.1
 
 changedir =
   tests/opentelemetry-docker-tests/tests