[FIX] web: invalid image placeholder resizing

Access `/web/image/82303?height=16`, traceback because the placeholder
image cannot be resized to `"16"`.

closes odoo/odoo#92891

Signed-off-by: Julien Castiaux <juc@odoo.com>

addons/web/controllers/binary.py

@@ -142,7 +142,7 @@ class Binary(http.Controller):
                 width, height = image_guess_size_from_field_name(field)
             record = request.env.ref('web.image_placeholder').sudo()
             stream = request.env['ir.binary']._get_image_stream_from(
-                record, 'raw', width=width, height=height, crop=crop,
+                record, 'raw', width=int(width), height=int(height), crop=crop,
             )
 
         send_file_kwargs = {'as_attachment': download}