Upgrade edge-action extension to API version 2025-12-01-preview (Azure#9503)

- Upgrade to API version 2025-12-01-preview
- Remove add-attachment and delete-attachment commands (no longer supported in new API)
- Retain custom fixes for get-version-code and swap-default commands

Co-authored-by: Danny Tundwe (from Dev Box) <dannytundwe@microsoft.com>

Author: tundwed

src/edge-action/HISTORY.rst

@@ -3,6 +3,11 @@
 Release History
 ===============
 
+1.0.0b3
+++++++
+* Upgrade to API version 2025-12-01-preview
+* Remove `add-attachment` and `delete-attachment` commands (no longer supported in new API version)
+
 1.0.0b2
 ++++++
 * Fix 415 Unsupported Media Type error for `get-version-code` and `swap-default` POST operations by adding required Content-Type header and empty JSON body

src/edge-action/azext_edge_action/aaz/latest/edge_action/__init__.py

@@ -9,10 +9,8 @@
 # flake8: noqa
 
 from .__cmd_group import *
-from ._add_attachment import *
 from ._create import *
 from ._delete import *
-from ._delete_attachment import *
 from ._list import *
 from ._show import *
 from ._update import *