fix: avoid catch (...) for expected import numpy failures (#3974)

* Replace import numpy catch (...) with catch (error_already_set)

* Add missing const (not sure how those got lost).

tests/test_numpy_array.cpp

@@ -162,7 +162,7 @@ static int data_i = 42;
 TEST_SUBMODULE(numpy_array, sm) {
     try {
         py::module_::import("numpy");
-    } catch (...) {
+    } catch (const py::error_already_set &) {
         return;
     }