PyYAML bug workaround

Change-Id: Ifecf6be5c7f93b1a7f519b353906c7d70660832b
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
diff --git a/requirements-dev.txt b/requirements-dev.txt
index aafb45a..4378db6 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -75,7 +75,7 @@
     # via
     #   -r https://osm.etsi.org/gitweb/?p=osm/common.git;a=blob_plain;f=requirements.txt;hb=paas
     #   temporalio
-pyyaml==5.4.1
+pyyaml==5.3.1
     # via
     #   -r https://osm.etsi.org/gitweb/?p=osm/IM.git;a=blob_plain;f=requirements.txt;hb=paas
     #   -r https://osm.etsi.org/gitweb/?p=osm/common.git;a=blob_plain;f=requirements.txt;hb=paas