Fix invalid UTF8 strings being copied into the Python console

Add a ensure_utf8 argument to WM_clipboard_text_get so callers don't
have to handle validation themselves.

Copying non-utf8 text into the Python console and buttons was possible,
causing invalid cursor position and a UnicodeDecodeError accessing
ConsoleLine.body from Python.

source/blender/python/intern/bpy_rna_types_capi.c

@@ -111,7 +111,8 @@ PyDoc_STRVAR(pyrna_WindowManager_clipboard_doc, "Clipboard text storage.\n\n:typ
 static PyObject *pyrna_WindowManager_clipboard_get(PyObject *UNUSED(self), void *UNUSED(flag))
 {
   int text_len = 0;
-  char *text = WM_clipboard_text_get(false, &text_len);
+  /* No need for UTF8 validation as #PyC_UnicodeFromBytesAndSize handles invalid byte sequences. */
+  char *text = WM_clipboard_text_get(false, false, &text_len);
   PyObject *result = PyC_UnicodeFromBytesAndSize(text ? text : "", text_len);
   if (text != NULL) {
     MEM_freeN(text);