File `calendar_mismatch.scss` was wrongly in a `css` folder while it should be in a `scss` folder according to the guidelines. And set the correct `type="text/scss"` instead of `type="text/css"` for a .scss file. closes odoo/odoo#34478 Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>