fix: skip tests that require pyarrow when it is not installed (#3114)

* fix: skip tests that require pyarrow when it is not installed

* style: pre-commit fixes

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

tests-cuda/test_2922a_new_cuda_kernels.py

@@ -651,6 +651,8 @@ def test_2425_forms_from_type_regular():
 
 
 def test_2425_forms_from_type_categorical():
+    pytest.importorskip("pyarrow")
+
     array = ak.str.to_categorical(["do", "re", "mi", "fa", "so"])
 
     cuda_array = ak.to_backend(array, "cuda")
@@ -663,6 +665,8 @@ def test_2425_forms_from_type_categorical():
 
 
 def test_2425_forms_from_type_categorical_option():
+    pytest.importorskip("pyarrow")
+
     array = ak.str.to_categorical(["do", "re", "mi", "fa", "so", None])
 
     cuda_array = ak.to_backend(array, "cuda")
@@ -1180,6 +1184,8 @@ def test_1823_fill_none_axis_none():
 
 
 def test_1671_categorical_type():
+    pytest.importorskip("pyarrow")
+
     array1 = ak.Array(["one", "two", "one", "one"])
     array2 = ak.str.to_categorical(array1)
 
@@ -1197,6 +1203,8 @@ def test_1671_categorical_type():
 
 
 def test_1671_categorical_type_to_categorical():
+    pytest.importorskip("pyarrow")
+
     array1 = ak.Array(["one", "two", "one", "one"])
     array2 = ak.str.to_categorical(array1)