build(deps): bump github.com/spf13/viper from 1.16.0 to 1.18.2

Bumps [github.com/spf13/viper](https://github.com/spf13/viper) from 1.16.0 to 1.18.2.
- [Release notes](https://github.com/spf13/viper/releases)
- [Commits](spf13/viper@v1.16.0...v1.18.2)

---
updated-dependencies:
- dependency-name: github.com/spf13/viper
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -16,11 +16,11 @@ require (
 	github.com/shurcooL/go v0.0.0-20200502201357-93f07166e636
 	github.com/sirupsen/logrus v1.9.3
 	github.com/spf13/cobra v1.8.0
-	github.com/spf13/viper v1.16.0
+	github.com/spf13/viper v1.18.2
 	github.com/stretchr/testify v1.8.4
 	github.com/theupdateframework/go-tuf v0.7.0
 	github.com/theupdateframework/notary v0.7.0
-	golang.org/x/exp v0.0.0-20221204150635-6dcec336b2bb
+	golang.org/x/exp v0.0.0-20230905200255-921286631fa9
 	golang.org/x/sys v0.15.0
 	google.golang.org/api v0.154.0
 	gopkg.in/yaml.v2 v2.4.0
@@ -32,9 +32,9 @@ require (
 	cloud.google.com/go/compute/metadata v0.2.3 // indirect
 	cloud.google.com/go/iam v1.1.5 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.3 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
-	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/go-logr/logr v1.3.0 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
@@ -49,23 +49,27 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/miekg/pkcs11 v1.0.3-0.20190429190417-a667d056470f // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
-	github.com/pelletier/go-toml/v2 v2.0.8 // indirect
+	github.com/pelletier/go-toml/v2 v2.1.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/sagikazarmark/locafero v0.4.0 // indirect
+	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
 	github.com/secure-systems-lab/go-securesystemslib v0.7.0 // indirect
-	github.com/spf13/afero v1.9.5 // indirect
-	github.com/spf13/cast v1.5.1 // indirect
-	github.com/spf13/jwalterweatherman v1.1.0 // indirect
+	github.com/sourcegraph/conc v0.3.0 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/spf13/cast v1.6.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
-	github.com/subosito/gotenv v1.4.2 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/thales-e-security/pool v0.0.2 // indirect
 	go.opencensus.io v0.24.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.46.1 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.46.1 // indirect
 	go.opentelemetry.io/otel v1.21.0 // indirect
 	go.opentelemetry.io/otel/metric v1.21.0 // indirect
 	go.opentelemetry.io/otel/trace v1.21.0 // indirect
+	go.uber.org/atomic v1.9.0 // indirect
+	go.uber.org/multierr v1.9.0 // indirect
 	golang.org/x/crypto v0.16.0 // indirect
 	golang.org/x/net v0.19.0 // indirect
 	golang.org/x/oauth2 v0.15.0 // indirect