Decide if we want to ignore xs:integer schema validation errors

[kislyuk]

Element '{http://www.w3.org/2000/09/xmldsig#}X509SerialNumber': '133503482272988939655787341095582449805' is not a valid value of the atomic type 'xs:integer'

See discussion in https://gitlab.gnome.org/GNOME/libxml2/-/issues/353 (while it's informative as to the problem and workarounds, it makes it sound like this problem only occurs on 32-bit systems, which is not the case)

If we do want to ignore the errors, we should probably switch from assert/exception based validation to emitting a validation log and filtering any errors of this type out of it.