fix: exclude npmjs.com from CI link check

A browser user agent didn't help -- npmjs.com's bot protection blocks
GitHub Actions runners outright, confirmed by a failing CI run. The
link itself works fine; it's just unreachable from CI.

Author: ftrauernicht

.lychee.toml

@@ -9,9 +9,6 @@ max_retries = 3
 retry_wait_time = 5
 timeout = 20
 
-# Some hosts (e.g. npmjs.com) return 403 to non-browser user agents.
-user_agent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
-
 # Treat rate-limited responses as passing rather than failing CI -- a 429
 # means the host is alive and throttling us, not that the link is dead.
 accept = ["200..=299", "429"]
@@ -21,3 +18,10 @@ accept = ["200..=299", "429"]
 exclude_path = [
   "node_modules",
 ]
+
+# npmjs.com sits behind bot protection that blocks GitHub Actions runners
+# outright (a browser user agent alone didn't fix it -- confirmed by a
+# failing CI run) -- not a dead link, just unreachable from CI.
+exclude = [
+  '^https://(www\.)?npmjs\.com',
+]