Don't offer a code action for a diagnostic with no diagnostic "code"

Per the lsp spec, a diagnostic code, if one exists, should be a number
or a string.  At least one error message (the help message for missing
imports) doesn't include a code, so the parse_line function sets it to
"None".

When this happens, don't offer a code action for that diagnostic

Author: mtbentley

pylsp_mypy/plugin.py

@@ -604,6 +604,8 @@ def pylsp_code_actions(
     for diagnostic in context.get("diagnostics", []):
         if diagnostic["source"] != "mypy":
             continue
+        if diagnostic.get("code") is None:
+            continue
         code = diagnostic["code"]
         lineNumberEnd = diagnostic["range"]["end"]["line"]
         line = document.lines[lineNumberEnd]