chore: Pin GitOps engine to v0.6.0 (#8706)

Signed-off-by: Yuan Tang <terrytangyuan@gmail.com>

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/TomOnTime/utfutil v0.0.0-20180511104225-09c41003ee1d
 	github.com/alicebob/miniredis v2.5.0+incompatible
 	github.com/alicebob/miniredis/v2 v2.14.2
-	github.com/argoproj/gitops-engine v0.5.1-0.20220215202024-c517b47f2f2f
+	github.com/argoproj/gitops-engine v0.6.0
 	github.com/argoproj/notifications-engine v0.3.1-0.20220127183449-91deed20b998
 	github.com/argoproj/pkg v0.11.1-0.20211203175135-36c59d8fafe0
 	github.com/bombsimon/logrusr/v2 v2.0.1

go.sum

@@ -130,8 +130,8 @@ github.com/antonmedv/expr v1.8.9/go.mod h1:5qsM3oLGDND7sDmQGDXHkYfkjYMUX14qsgqmH
 github.com/apache/thrift v0.12.0/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/apache/thrift v0.13.0/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/appscode/go v0.0.0-20190808133642-1d4ef1f1c1e0/go.mod h1:iy07dV61Z7QQdCKJCIvUoDL21u6AIceRhZzyleh2ymc=
-github.com/argoproj/gitops-engine v0.5.1-0.20220215202024-c517b47f2f2f h1:eO09b/oPk5di9q1HdO68/zdZkjXEhmO4aS4RsWHpDWQ=
-github.com/argoproj/gitops-engine v0.5.1-0.20220215202024-c517b47f2f2f/go.mod h1:UJrK2YMBUbwJZue68mXhSDw+T52egdZWAU1F5cK34ko=
+github.com/argoproj/gitops-engine v0.6.0 h1:Tnh6kUUVuBV0m3gueYIymAeErWl9XNN9O9JcOoNM0vU=
+github.com/argoproj/gitops-engine v0.6.0/go.mod h1:pRgVpLW7pZqf7n3COJ7UcDepk4cI61LAcJd64Q3Jq/c=
 github.com/argoproj/notifications-engine v0.3.1-0.20220127183449-91deed20b998 h1:V9RDg+IZeebnm3XjkfkbN07VM21Fu1Cy/RJNoHO++VM=
 github.com/argoproj/notifications-engine v0.3.1-0.20220127183449-91deed20b998/go.mod h1:5mKv7zEgI3NO0L+fsuRSwBSY9EIXSuyIsDND8O8TTIw=
 github.com/argoproj/pkg v0.11.1-0.20211203175135-36c59d8fafe0 h1:Cfp7rO/HpVxnwlRqJe0jHiBbZ77ZgXhB6HWlYD02Xdc=