test(docs): Exclude GitHub pkgs from link check (#4312)

Author: max-sixty

.config/.markdown-link-check-local.json

@@ -5,6 +5,10 @@
       "_comment_2": "If some third-party website breaks a link, we cover that in ./.markdown-link-check-all.json",
       "_comment_3": "So this excludes anything that's not a relative link to a file in our repo or a link to our file on the web.",
       "pattern": "^(?!https://github\\.com/(PRQL|prql)|https://prql-lang\\.org|https://raw\\.githubusercontent\\.com/(PRQL|prql)|[./]+|file://).*$"
+    },
+    {
+      "_comment": "`https://github.com/PRQL/prql/pkgs/container/` seems to fail extremely frequently from CI, more so than other GitHub links. So ignoring.",
+      "pattern": "^https://github.com/PRQL/prql/pkgs/container"
     }
   ],
   "httpHeaders": [