Update pyyaml version to 6.0.1 in IM requirements

Change-Id: I8a7d5e59710a5355eb8ea318ce39e2b6eb7ef07e
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/requirements.in b/requirements.in
index 94c2eb9..c34778a 100644
--- a/requirements.in
+++ b/requirements.in
@@ -15,4 +15,4 @@
 
 pyang
 pyangbind
-pyyaml==5.4.1
\ No newline at end of file
+pyyaml==6.0.1