Deprecate RecordEntry.validate

This function is no longer meant to be used, since there's a superior
alternative available.

src/installer/records.py

@@ -146,6 +146,10 @@ def __eq__(self, other: object) -> bool:
     def validate(self, data: bytes) -> bool:
         """Validate that ``data`` matches this instance.
 
+        .. attention::
+            .. deprecated:: 0.8.0
+                Use :py:meth:`validate_stream` instead, with ``BytesIO(data)``.
+
         :param data: Contents of the file corresponding to this instance.
         :return: whether ``data`` matches hash and size.
         """