fix import in script for use by typer (#982)

Co-authored-by: Eddie Schlafly <[email protected]>

pyproject.toml

@@ -64,6 +64,8 @@ dev = [
 ]
 sdp = [
     'stpreview>=0.5.1',
+    'typer',
+    'typing_extensions',
 ]
 
 [project.urls]

romancal/scripts/static_preview.py

@@ -1,12 +1,9 @@
 from pathlib import Path
-from typing import TYPE_CHECKING, Optional
+from typing import Optional
 
 import asdf
 import numpy
 
-if TYPE_CHECKING:
-    from typing_extensions import Annotated
-
 
 def command():
     try:
@@ -17,6 +14,7 @@ def command():
             percentile_normalization,
             write_image,
         )
+        from typing_extensions import Annotated
     except (ImportError, ModuleNotFoundError):
         raise ImportError(
             'SDP requirements not installed; do `pip install "romancal[sdp]"`'