Move back to upstream for umoci import, go mod tidy.

Serge's change for avoiding chmod +r if not necessary was merged
upstream under opencontainers/umoci#499.
We do not need to use the project-stacker fork any more.

Dropping that and updating to current umoci main looks like this:

   go mod get github.com/opencontainers/umoci@main
   go mod edit -dropreplace github.com/opencontainers/umoci
   go mod tidy

Signed-off-by: Scott Moser <smoser@brickies.net>

go.mod

@@ -20,17 +20,17 @@ require (
 	github.com/moby/buildkit v0.11.4
 	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.1.0-rc4
-	github.com/opencontainers/umoci v0.4.8-0.20220412065115-12453f247749
+	github.com/opencontainers/umoci v0.4.8-0.20230920134428-7dc114a520bc
 	github.com/pkg/errors v0.9.1
 	github.com/pkg/xattr v0.4.9
 	github.com/sirupsen/logrus v1.9.0
 	github.com/smartystreets/goconvey v1.7.2
-	github.com/stretchr/testify v1.8.2
+	github.com/stretchr/testify v1.8.4
 	github.com/twmb/algoimpl v0.0.0-20170717182524-076353e90b94
 	github.com/udhos/equalfile v0.3.0
 	github.com/urfave/cli/v2 v2.25.0
 	github.com/vbatts/go-mtree v0.5.3
-	golang.org/x/sys v0.8.0
+	golang.org/x/sys v0.10.0
 	golang.org/x/term v0.8.0
 	gopkg.in/yaml.v2 v2.4.0
 	sigs.k8s.io/bom v0.5.2-0.20230512052447-fef7b03b207d
@@ -158,7 +158,7 @@ require (
 	github.com/nwaples/rardecode v1.1.3 // indirect
 	github.com/oklog/ulid v1.3.1 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
-	github.com/opencontainers/runc v1.1.4 // indirect
+	github.com/opencontainers/runc v1.1.8 // indirect
 	github.com/opencontainers/runtime-spec v1.1.0-rc.1 // indirect
 	github.com/opencontainers/selinux v1.11.0 // indirect
 	github.com/package-url/packageurl-go v0.1.1-0.20220428063043-89078438f170 // indirect
@@ -171,7 +171,7 @@ require (
 	github.com/prometheus/common v0.39.0 // indirect
 	github.com/rivo/uniseg v0.4.3 // indirect
 	github.com/robfig/cron/v3 v3.0.1 // indirect
-	github.com/rootless-containers/proto/go-proto v0.0.0-20210921234734-69430b6543fb // indirect
+	github.com/rootless-containers/proto/go-proto v0.0.0-20230421021042-4cd87ebadd67 // indirect
 	github.com/rs/zerolog v1.29.1 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/sassoftware/go-rpmutils v0.2.0 // indirect
@@ -223,7 +223,7 @@ require (
 	golang.org/x/xerrors v0.0.0-20220907171357-04be3eba64a2 // indirect
 	google.golang.org/genproto v0.0.0-20230403163135-c38d8f061ccd // indirect
 	google.golang.org/grpc v1.54.0 // indirect
-	google.golang.org/protobuf v1.30.0 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/square/go-jose.v2 v2.6.0 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect
@@ -234,5 +234,3 @@ require (
 )
 
 replace stackerbuild.io/stacker-bom => github.com/project-stacker/stacker-bom v0.0.0-20230522080732-de2712897250
-
-replace github.com/opencontainers/umoci => github.com/project-stacker/umoci v0.0.0-20230913180343-4d41477ef0ba