Update version of PyYAML

Change-Id: Ib65a9712db84ea4346fdea11c5554845dc2d52ec
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 46fdb1f..9f8bd6d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -44,5 +44,5 @@
     # via
     #   -r https://osm.etsi.org/gitweb/?p=osm/common.git;a=blob_plain;f=requirements.txt;hb=master
     #   motor
-pyyaml==5.4.1
+pyyaml==6.0.1
     # via -r https://osm.etsi.org/gitweb/?p=osm/common.git;a=blob_plain;f=requirements.txt;hb=master