Remove pre-0.8 support, decouple Collection/Catalog migration

Author: duckontheweb

pystac/serialization/identify.py

@@ -87,7 +87,7 @@ class STACVersionRange:
 
     def __init__(
         self,
-        min_version: Union[str, STACVersionID] = "0.4.0",
+        min_version: Union[str, STACVersionID] = "0.8.0",
         max_version: Optional[Union[str, STACVersionID]] = None,
     ):
         if isinstance(min_version, str):

pystac/serialization/migrate.py

@@ -17,8 +17,6 @@
 def _migrate_catalog(
     d: Dict[str, Any], version: STACVersionID, info: STACJSONDescription
 ) -> None:
-    if version < "0.8":
-        d["stac_extensions"] = list(info.extensions)
     d["type"] = STACType.CATALOG
 
 
@@ -37,7 +35,6 @@ def _migrate_collection_summaries(
 def _migrate_collection(
     d: Dict[str, Any], version: STACVersionID, info: STACJSONDescription
 ) -> None:
-    _migrate_catalog(d, version, info)
     d["type"] = STACType.COLLECTION
     _migrate_collection_summaries(d, version, info)