Use more specific exception type for imap decoding (#104227)

* Use more specific exception type for imap decoding

* Only catch ValueError

homeassistant/components/imap/coordinator.py

@@ -167,7 +167,7 @@ def _decode_payload(part: Message) -> str:
             """
             try:
                 return str(part.get_payload(decode=True).decode(self._charset))
-            except Exception:  # pylint: disable=broad-except
+            except ValueError:
                 return str(part.get_payload())
 
         part: Message