Update type for all save_dir in plots

Author: sgreenbury

src/acbm/assigning/plots.py

@@ -17,7 +17,7 @@ def plot_workzone_assignment_line(
     n: int,
     selection_type: str = "random",
     sort_by: str = "assigned",
-    save_dir: Optional[str] = None,
+    save_dir: str | Path | None = None,
     display: bool = False,
 ):
     """
@@ -136,7 +136,7 @@ def plot_workzone_assignment_heatmap(
     n: int,
     selection_type: str = "random",
     sort_by: str = "assigned",
-    save_dir: Optional[str] = None,
+    save_dir: str | Path | None = None,
     display: bool = False,
 ):
     """
@@ -240,7 +240,7 @@ def plot_desire_lines(
     bin_size: int,
     boundaries: gpd.GeoDataFrame,
     sample_size: Optional[int] = None,
-    save_dir: str | None | Path = None,
+    save_dir: str | Path | None = None,
 ) -> None:
     """
     Plots activity chains for a given activity type, bin size, geographical boundaries, and an optional sample size.
@@ -389,7 +389,7 @@ def plot_scatter_actual_reported(
     title_prefix: str,
     activity_type: str,
     activity_type_col: str,
-    save_dir: str | None | Path = None,
+    save_dir: str | Path | None = None,
     display: bool = False,
 ):
     """