added secret for github example

Author: yunchengyang515

.github/workflows/stackql-exec.yml

@@ -47,4 +47,6 @@ jobs:
                   SHOW PROVIDERS;
                   select total_private_repos
                   from github.orgs.orgs
-                  where org = 'stackql';"
+                  where org = 'stackql';"
+        env: 
+          STACKQL_GITHUB_CREDS: ${{  secrets.STACKQL_GITHUB_CREDS }}