CI: Explicitly check environment variable against `None` in matrix.py

For consistency with `GITHUB_OUTPUT` at the bottom.

diff --git a/.github/matrix.py b/.github/matrix.py
index e03453aa4d891df3c2b8dc64c18905ec667d1533..c58bb7acd4b75107e2dc3c84b8bff40e088e6108 100755 (executable)
--- a/.github/matrix.py
+++ b/.github/matrix.py
@@ -29,7 +29,7 @@ def clean_ssl(ssl):
 @functools.lru_cache(5)
 def determine_latest_openssl(ssl):
     headers = {}
-    if environ.get('GITHUB_TOKEN'):
+    if environ.get('GITHUB_TOKEN') is not None:
         headers["Authorization"] = "token {}".format(environ.get('GITHUB_TOKEN'))
 
     request = urllib.request.Request('https://api.github.com/repos/openssl/openssl/tags', headers=headers)