fix: add aws-eusc partition support, remove original_template_dict from Stack.__eq__

- Add eusc- region prefix handling to derive_partition (aws-eusc) and
  derive_url_suffix (amazonaws.eu) for the AWS European Sovereign Cloud
- Revert us-iso-/us-isob- ADC partition branches — not supported
  elsewhere in the SAM CLI codebase
- Remove original_template_dict from Stack.__eq__ — it is operational
  metadata for deployment, not part of the stack's semantic identity.
  Including it caused stacks created via different code paths to compare
  as unequal even when semantically identical

Author: bnusunny

samcli/lib/cfn_language_extensions/utils.py

@@ -31,10 +31,8 @@ def derive_partition(region: str) -> str:
         return "aws-cn"
     elif region.startswith("us-gov-"):
         return "aws-us-gov"
-    elif region.startswith("us-isob-"):
-        return "aws-iso-b"
-    elif region.startswith("us-iso-"):
-        return "aws-iso"
+    elif region.startswith("eusc-"):
+        return "aws-eusc"
     else:
         return "aws"
 
@@ -43,10 +41,8 @@ def derive_url_suffix(region: str) -> str:
     """Derive the AWS URL suffix from the region."""
     if region.startswith("cn-"):
         return "amazonaws.com.cn"
-    elif region.startswith("us-isob-"):
-        return "sc2s.sgov.gov"
-    elif region.startswith("us-iso-"):
-        return "c2s.ic.gov"
+    elif region.startswith("eusc-"):
+        return "amazonaws.eu"
     else:
         return "amazonaws.com"
 

samcli/lib/providers/provider.py

@@ -728,7 +728,6 @@ def __eq__(self, other: Any) -> bool:
                 and self.stack_id == other.stack_id
                 and self.stack_path == other.stack_path
                 and self.template_dict == other.template_dict
-                and self.original_template_dict == other.original_template_dict
             )
         return False