fix: initial DNS timeout issue (#653)

ml-testing-toolkit-cli/values.yaml

@@ -21,6 +21,7 @@ restartPolicy: Never
 
 ## Bash script for TTK CLI
 script: |
+    until nslookup github.com; do sleep 5;done;
     echo "Downloading the test collection...";
     wget {{ .Values.config.testCasesZipUrl }} -O downloaded-test-collections.zip;
     mkdir tmp_test_cases;