deprecate: Show warning only in 2.1+, update messaging

- Module is temporary, provided to assist migration from pre-2.0
- Deprecation warning only appears in 2.1+
- Will be removed in 2.2

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: dimitri-yatsenko

src/datajoint/migrate.py

@@ -5,9 +5,10 @@
 Codec system, particularly for upgrading blob columns to use
 explicit `<blob>` type declarations.
 
-.. deprecated:: 2.0.0
-    This module is deprecated and will be removed in DataJoint 2.2.
-    Complete your migrations before upgrading to 2.2.
+.. note::
+    This module is provided temporarily to assist with migration from pre-2.0.
+    It will be deprecated in DataJoint 2.1 and removed in 2.2.
+    Complete your migrations while on DataJoint 2.0.
 
 Note on Terminology
 -------------------
@@ -24,13 +25,16 @@
 from typing import TYPE_CHECKING
 
 from .errors import DataJointError
-
-warnings.warn(
-    "datajoint.migrate is deprecated and will be removed in DataJoint 2.2. "
-    "Complete your schema migrations before upgrading to 2.2.",
-    DeprecationWarning,
-    stacklevel=2,
-)
+from . import __version__
+
+# Show deprecation warning starting in 2.1
+if __version__ >= "2.1":
+    warnings.warn(
+        "datajoint.migrate is deprecated and will be removed in DataJoint 2.2. "
+        "Complete your schema migrations before upgrading.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
 
 if TYPE_CHECKING:
     from .schemas import Schema