Bug 1753211 - switch yaml v4 call from `safeLoad` to `load` to fix Custom Actions (#7372)

yaml v4 made the `load` function safe and dropped the `safeLoad` one. The update
to yaml v4 had landed in
933d8dfb69

ui/job-view/CustomJobActions.jsx

@@ -131,7 +131,7 @@ class CustomJobActions extends React.PureComponent {
     let input = null;
     if (validate && payload) {
       try {
-        input = jsyaml.safeLoad(payload);
+        input = jsyaml.load(payload);
       } catch (e) {
         this.setState({ triggering: false });
         notify(`YAML Error: ${e.message}`, 'danger');