Bump golang.org/x/net in /exporter/googlecloudpubsubexporter

Bumps [golang.org/x/net](https://github.com/golang/net) from 0.21.0 to 0.23.0.
- [Commits](golang/net@v0.21.0...v0.23.0)

---
updated-dependencies:
- dependency-name: golang.org/x/net
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

exporter/googlecloudpubsubexporter/go.mod

@@ -65,11 +65,11 @@ require (
 	go.opentelemetry.io/otel/sdk v1.24.0 // indirect
 	go.opentelemetry.io/otel/sdk/metric v1.24.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/crypto v0.19.0 // indirect
-	golang.org/x/net v0.21.0 // indirect
+	golang.org/x/crypto v0.21.0 // indirect
+	golang.org/x/net v0.23.0 // indirect
 	golang.org/x/oauth2 v0.17.0 // indirect
 	golang.org/x/sync v0.6.0 // indirect
-	golang.org/x/sys v0.17.0 // indirect
+	golang.org/x/sys v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	google.golang.org/appengine v1.6.8 // indirect