Update en.xml to add apc (Levantine Arabic)

[a455bcd9]

Adding apc Levantine Arabic, surprisingly not present even though it was included in the 43 release ( https://cldr.unicode.org/index/downloads/cldr-43 ).

CLDR-_____

• [ ] This PR completes the ticket.

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[srl295]

@a455bcd9 please file a ticket unicode-org.atlassian.net and make the commit and PR start with that (CLDR-00000 Update en.xml to add apc…)

Process wise, https://unicode-org.atlassian.net/browse/CLDR-15663 should cause this to be sorted out at least later in the cycle.