[BUG] fn:parse-xml, xmldb:store fail to parse string starting with BOM

[line-o]

Describe the bug

Evaluating one of the below main modules will raise error FODC0006.

[...] not a well-formed XML document.: Document is not valid. Fatal (1,1) : Content is not allowed in prolog. [...]

Queries:

parse-xml("&#xFEFF;<root/>")

xmldb:store("/db", "test.xml", "&#xFEFF;<root/>")

Expected behavior

Both commands to work with or without BOM at the start of the string.
BaseX does ignore the BOM and this an issue was opened for Saxon too.

To Reproduce

xquery version "3.1";

module namespace t="http://exist-db.org/xquery/test";

declare namespace test="http://exist-db.org/xquery/xqsuite";

declare variable $t:string := "&#xFEFF;<root/>";

declare
    %test:tearDown
function t:tearDown() {
    xmldb:remove("/db/test.xml")
};

declare
    %test:assertTrue
function t:test-parse-bom() {
  exists(parse-xml($t:string))
};

declare
    %test:assertTrue
function t:test-store-bom() {
  exists(xmldb:store("/db", "test.xml", $t:string))
};

Context (please always complete the following information)

• Build: eXist-6.3.0
• Java: 1.8.0_352
• OS: Mac OS X 15.2

Additional context

• How is eXist-db installed? built from source
• Any custom changes in e.g. conf.xml? none