dtype_from_numpy: "l"/"L"

Fix: `TypeError: data type 'ulong' not understood` on
GCC 9 w/ Python 3.10 on Linux.

Author: ax3l

include/openPMD/binding/python/Numpy.hpp

@@ -58,8 +58,7 @@ inline Datatype dtype_from_numpy(pybind11::dtype const dt)
         return Datatype::INT;
     else if (dt.char_() == pybind11::dtype("int_").char_())
         return Datatype::LONG;
-    else if (dt.char_() == pybind11::dtype("long").char_()) // alias used on
-                                                            // Win64
+    else if (dt.char_() == pybind11::dtype("l").char_()) // alias used on Win64
         return Datatype::LONG;
     else if (dt.char_() == pybind11::dtype("longlong").char_())
         return Datatype::LONGLONG;
@@ -69,8 +68,7 @@ inline Datatype dtype_from_numpy(pybind11::dtype const dt)
         return Datatype::UINT;
     else if (dt.char_() == pybind11::dtype("uint").char_())
         return Datatype::ULONG;
-    else if (dt.char_() == pybind11::dtype("ulong").char_()) // alias used on
-                                                             // Win64
+    else if (dt.char_() == pybind11::dtype("L").char_()) // alias used on Win64
         return Datatype::ULONG;
     else if (dt.char_() == pybind11::dtype("ulonglong").char_())
         return Datatype::ULONGLONG;