[BF] Fix crash in switch config list if array_sum contains non-integer

[listerr]

Fix crash in php8.3 if array_sum contains non-integers from scaleBits()

[2025-02-20 16:24:49] production.ERROR: array_sum(): Addition is not supported on type string {"userId":725,"exception":"[object] (ErrorException(code: 0): array_sum(): Addition is not supported on type string at /srv/ixpmanager/resources/views/switches/configuration.foil.php:179)

Downgraded to php8.1 for now, but while I was on 8.3, fixed this error.

In addition to the above, I have:

• ensured all relevant template output is escaped to avoid XSS attached with <?= $t->ee( $data ) ?> or equivalent.
• ensured appropriate checks against user privilege / resources accessed
• API calls (particular for add/edit/delete/toggle) are not implemented with GET and use CSRF tokens to avoid CSRF attacks