Decimal comma doesn't work

[TheOneTEM]

Device: Google Pixel 6 Pro
Keyboard: Gboard
Browser: Mozilla Firefox (latest)

Issue description:
In the "nytt utlägg" page, where you enter the subtotals under each budget post, the mobile client allows the use of a decimal comma (','), as is the convention for decimal numbers in Sweden (and most of Europe). However, when the decimal comma is used, I was not allowed to save the utlägg.

Reproduction steps:
Follow the regular "new utlägg" flow, and enter a decimal amount as follows, using the mobile keyboard: "69,67". The "save and continue" button should do nothing.

Proposed solutions:

1. Disable the decimal comma on mobile numeric keyboards.
2. Some kind of error popup when entering an invalid subtotal or a valid subtotal in an invalid format.