refactor: trigger metadata retrieval only during DeltaTable.metadata (

#1979)

# Description
Triggers metadata retrieval only on metadata call, this is a better
approach otherwise we need to add it after each method that does an
alteration to the table config. Also now it will only be triggered if
the user actually wants to retrieve the metadata.

Co-authored-by: Robert Pack <42610831+roeap@users.noreply.github.com>

python/deltalake/table.py

@@ -264,7 +264,6 @@ def __init__(
             without_files=without_files,
             log_buffer_size=log_buffer_size,
         )
-        self._metadata = Metadata(self._table)
 
     @classmethod
     def from_data_catalog(
@@ -499,7 +498,7 @@ def metadata(self) -> Metadata:
         Returns:
             the current Metadata registered in the transaction log
         """
-        return self._metadata
+        return Metadata(self._table)
 
     def protocol(self) -> ProtocolVersions:
         """