[FIX] remove import statments that make java a non-optional dependency

if TYPE_CHECKING:
    from ashlar.reg import EdgeAligner, Mosaic

Is always removed by ruff linter. Removing the return types and the import statements to ensure that java dependency is only required for the stitching code.

Author: sophiamaedler

src/scportrait/tools/stitch/_stitch.py

@@ -18,7 +18,6 @@
     mmap_array_from_path,
     redefine_temp_location,
 )
-from ashlar.reg import EdgeAligner, Mosaic
 from tqdm import tqdm
 
 from scportrait.io.daskmmap import dask_array_from_path
@@ -330,7 +329,7 @@ def generate_thumbnail(self, scale: float | None = 0.05) -> None:
         if rescale:
             self.thumbnail = rescale_image(self.thumbnail, rescale_range)
 
-    def _initialize_aligner(self) -> EdgeAligner:
+    def _initialize_aligner(self):
         """Initialize the aligner for aligning the image tiles.
 
         Returns:
@@ -370,7 +369,7 @@ def _perform_alignment(self):
 
         print("Alignment complete.")
 
-    def _initialize_mosaic(self) -> Mosaic:
+    def _initialize_mosaic(self):
         """Initialize the mosaic object for assembling the image tiles.
 
         Returns: