python-ubus: backport patch for newer Python

Build is failing for a while now with error:
```
14.3.0_musl/usr/include -I/builder/shared-workdir/build/sdk/staging_dir/toolchain-mipsel_24kc_gcc-14.3.0_musl/include -I/builder/shared-workdir/build/sdk/staging_dir/toolchain-mipsel_24kc_gcc-14.3.0_musl/include/fortify -I/builder/shared-workdir/build/sdk/staging_dir/target-mipsel_24kc_musl/usr/include/python3.14 -fPIC -I/builder/shared-workdir/build/sdk/staging_dir/target-mipsel_24kc_musl/usr/include/python3.14 -c ./ubus_python.c -o build/temp.linux-mipsel-cpython-314/ubus_python.o
./ubus_python.c: In function 'ubus_python_add':
./ubus_python.c:1081:17: error: implicit declaration of function 'PyEval_CallMethod'; did you mean 'PyObject_CallMethod'? [-Wimplicit-function-declaration]
 1081 |                 PyEval_CallMethod(python_alloc_list, "pop", "");
      |                 ^~~~~~~~~~~~~~~~~
      |                 PyObject_CallMethod
error: command '/builder/shared-workdir/build/sdk/staging_dir/toolc
```

This has been fixed on version 0.1.3, but that hasn't been
published to pypi yet.

Also add test.sh

Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>
(cherry picked from commit 29e685e1f8)

lang/python/python-ubus/test.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+
+[ "$1" = python3-ubus ] || exit 0
+
+python3 - << 'EOF'
+import ubus
+
+# Constants must be present
+assert hasattr(ubus, "BLOBMSG_TYPE_STRING"), "missing BLOBMSG_TYPE_STRING"
+assert hasattr(ubus, "BLOBMSG_TYPE_BOOL"),   "missing BLOBMSG_TYPE_BOOL"
+assert hasattr(ubus, "BLOBMSG_TYPE_INT32"),  "missing BLOBMSG_TYPE_INT32"
+
+# Not connected by default
+assert ubus.get_connected() is False, "should not be connected on import"
+assert ubus.get_socket_path() is None, "socket path should be None when not connected"
+
+# Connecting to a non-existent socket must raise IOError
+try:
+    ubus.connect(socket_path="/non/existing/ubus.sock")
+    raise AssertionError("expected IOError for missing socket")
+except IOError:
+    pass
+
+# Operations that require a connection must raise RuntimeError when disconnected
+for fn, args in [
+    (ubus.disconnect, ()),
+    (ubus.send,       ("event", {})),
+    (ubus.loop,       (1,)),
+    (ubus.objects,    ()),
+]:
+    try:
+        fn(*args)
+        raise AssertionError(f"{fn.__name__} should raise RuntimeError when not connected")
+    except RuntimeError:
+        pass
+EOF