KM02905: ERROR_UnicodeSetHasStrings

The provided uset uses multi-character strings, ({} notation, e.g. [żġħ{ie}{għ}]. ). Although full UnicodeSets support strings, LDML keyboards do not support multi-character strings in usets. To resolve this, reformat the uset to avoid the use of multi-character strings.

More on uset: https://www.unicode.org/reports/tr35/tr35-keyboards.html#element-uset