Merge pull request #19250 from Homebrew/ww/warn-pypi-info-no-dist

utils/pypi: warn when `pypi_info` fails due to missing sources

Library/Homebrew/utils/pypi.rb

@@ -86,7 +86,10 @@ module PyPI
         end
       end
 
-      return if dist.nil?
+      if dist.nil?
+        onoe "#{name} exists on PyPI but lacks a suitable source distribution"
+        return
+      end
 
       @pypi_info = [
         PyPI.normalize_python_package(json["info"]["name"]), dist["url"],