[facebook] improve 'date' extraction (#7151)

use 'created_time' as alternative when 'publish_time' isn't available

gallery_dl/extractor/facebook.py

@@ -99,9 +99,10 @@ class FacebookExtractor(Extractor):
                 '"message":{"delight_ranges"',
                 '"},"message_preferred_body"'
             ).rsplit('],"text":"', 1)[-1]),
-            "date": text.parse_timestamp(text.extr(
-                photo_page, '\\"publish_time\\":', ','
-            )),
+            "date": text.parse_timestamp(
+                text.extr(photo_page, '\\"publish_time\\":', ',') or
+                text.extr(photo_page, '"created_time":', ',')
+            ),
             "url": FacebookExtractor.decode_all(text.extr(
                 photo_page, ',"image":{"uri":"', '","'
             )),

test/results/facebook.py

@@ -122,6 +122,15 @@ __tests__ = (
     "caption"  : "A century of innovation parked side by side.\n\n📸: Vocabutesla via X",
 },
 
+{
+    "#url"     : "https://www.facebook.com/photo.php?fbid=989340003138066&set=pb.100061862277212.-2207520000&type=3",
+    "#comment" : "no 'publish_time' (#7151)",
+    "#category": ("", "facebook", "photo"),
+    "#class"   : facebook.FacebookPhotoExtractor,
+
+    "date"     : "dt:2025-02-25 15:00:09",
+},
+
 {
     "#url"     : "https://www.facebook.com/watch/?v=1165557851291824",
     "#category": ("", "facebook", "video"),