Update version of PyYAML

Change-Id: I9672c4cfc5e1aa3abcb67ee328fab299068c141c
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
diff --git a/requirements.txt b/requirements.txt
index 7de03f8..caa587d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -136,7 +136,7 @@
     #   oslo-serialization
     #   oslo-utils
     #   tempora
-pyyaml==5.4.1
+pyyaml==6.0.1
     # via
     #   -r requirements.in
     #   oslo-config