chore: add internet ckecker before telemetry

CONTRIBUTING.md

@@ -198,7 +198,6 @@ The application maintains the following exit codes.
 | 0         | Success                   |
 | 1         | Command execution error   |
 | 2         | Config resolution failure |
-| 3         | Telemetry failure         |
 
 ## Tests
 
@@ -262,19 +261,6 @@ npm i -g redocly-cli.tgz
 
 For other commands you'd have to do something similar.
 
-### Manual testing
-
-For manual testing in Kubernetes environments, we provide a preconfigured testing setup in the [`./k8s-testing`](./k8s-testing/) directory. This environment is specifically designed to test Redocly CLI performance in offline scenarios.
-
-The testing environment includes:
-
-- Kubernetes manifests for isolated testing
-- network policies to simulate offline/online conditions
-- automated test scripts for performance benchmarking
-- detailed documentation and troubleshooting guides
-
-See the [k8s-testing README](./k8s-testing/README.md) for complete setup and usage instructions.
-
 ### Performance benchmark
 
 To run the performance benchmark locally, you should have `hyperfine` (v1.16.1+) installed on your machine.