ENH small cleaning and optimizations accross the repo

.pre-commit-config.yaml

@@ -21,7 +21,7 @@ repos:
         files: sklearn_numba_dpex/
         additional_dependencies: [pytest==6.2.4]
 -   repo: https://github.com/PyCQA/isort
-    rev: 5.10.1
+    rev: 5.12.0
     hooks:
     -   id: isort
         files: sklearn_numba_dpex/

sklearn_numba_dpex/common/_utils.py

@@ -39,11 +39,14 @@ def _plus_closure(x, y):
     return _plus_closure
 
 
-def _divide():
-    def _divide_closure(x, y):
-        return x / y
+def _divide_by(divisor):
+    def _divide_by_fn():
+        def _divide_closure(x):
+            return x / divisor
 
-    return _divide_closure
+        return _divide_closure
+
+    return _divide_by_fn
 
 
 def _check_max_work_group_size(