[gdb/build] Redo poisoning of PyObject_CallMethod

[gdb/build] Redo poisoning of PyObject_CallMethod

In commit 764af878259 ("[gdb/python] Add typesafe wrapper around
PyObject_CallMethod") I added poisoning of PyObject_CallMethod:
...
/* Poison PyObject_CallMethod.  The typesafe wrapper gdbpy_call_method should be
   used instead.  */
template<typename... Args>
PyObject *
PyObject_CallMethod (Args...);
...

The idea was that subsequent code would be forced to use gdbpy_call_method
instead of PyObject_CallMethod.

However, that caused build issues with gcc 14 and python 3.13:
...
/usr/bin/ld: python/py-disasm.o: in function `gdb::ref_ptr<_object, gdbpy_ref_policy<_object> > gdbpy_call_method<unsigned int, long long>(_object*, char const*, unsigned int, long long)':
/data/vries/gdb/src/gdb/python/python-internal.h:207:(.text+0x384f): undefined reference to `_object* PyObject_CallMethod<_object*, char*, char*, unsigned int, long long>(_object*, char*, char*, unsigned int, long long)'
/usr/bin/ld: python/py-tui.o: in function `gdb::ref_ptr<_object, gdbpy_ref_policy<_object> > gdbpy_call_method<int>(_object*, char const*, int)':
/data/vries/gdb/src/gdb/python/python-internal.h:207:(.text+0x1235): undefined reference to `_object* PyObject_CallMethod<_object*, char*, char*, int>(_object*, char*, char*, int)'
/usr/bin/ld: python/py-tui.o: in function `gdb::ref_ptr<_object, gdbpy_ref_policy<_object> > gdbpy_call_method<int, int, int>(_object*, char const*, int, int, int)':
/data/vries/gdb/src/gdb/python/python-internal.h:207:(.text+0x12b0): undefined reference to `_object* PyObject_CallMethod<_object*, char*, char*, int, int, int>(_object*, char*, char*, int, int, int)'
collect2: error: ld returned 1 exit status
...

Fix this by poisoning without using templates.

Tested on x86_64-linux.