Strips whitespace and \n from loc before filtering urls from sitemap (#5728)

Fixes #5699 



#### Who can review?

Tag maintainers/contributors who might be interested:

@woodworker @LeSphax @johannhartmann

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

langchain/document_loaders/sitemap.py

@@ -79,8 +79,11 @@ class SitemapLoader(WebBaseLoader):
             if not loc:
                 continue
 
+            # Strip leading and trailing whitespace and newlines
+            loc_text = loc.text.strip()
+
             if self.filter_urls and not any(
-                re.match(r, loc.text) for r in self.filter_urls
+                re.match(r, loc_text) for r in self.filter_urls
             ):
                 continue