docs/linkcheck: Ignores https://www.gnome.org on CI platforms

It's replied with a 403 when run on the one from Github

docs/conf.py

@@ -13,9 +13,13 @@
 
 
 from importlib import metadata
+from os import environ
 import re
 
 
+CI = "CI" in environ
+
+
 # -- Project information -----------------------------------------------------
 
 project = "delb"
@@ -122,6 +126,14 @@
 html_domain_indices = False
 
 
+# -- Options for linkcheck ---------------------------------------------------
+
+if CI:
+    linkcheck_ignore = [
+        re.escape("https://www.gnome.org/"),
+    ]
+
+
 # -- Options for HTMLHelp output ---------------------------------------------
 
 # Output file base name for HTML help builder.