Fix a few bugs in run_example_ci_config tooling (#2577)

* Fix a few bugs in run_example_ci_config tooling

Github-deploy.yml had a fix to make it work out-of-the-box.

* Add flaky marker on test_ssl

(due to external internet access during the test, it does occasionally fail)

test/test_ssl.py

@@ -1,6 +1,8 @@
 import socket
 import textwrap
 
+import pytest
+
 from . import test_projects, utils
 
 project_with_ssl_tests = test_projects.new_c_project(
@@ -19,6 +21,7 @@ project_with_ssl_tests = test_projects.new_c_project(
 )
 
 
+@pytest.mark.flaky(reruns=2)
 def test(tmp_path):
     # this test checks that SSL is working in the build environment using
     # some checks in setup.py.