Add Levantine Arabic (apc)

This replaces ajp, according to ISO's decision to merge
it into apc:
https://iso639-3.sil.org/code/ajp

Follow-up to
3ba6536d85

data/langdb.yaml

@@ -17,9 +17,11 @@ languages:
   agq: [Latn, [AF], aghɨ̂m]
   ahr: [Deva, [AS], अहिराणी]
   ajg: [Latn, [AF], ajagbe]
-  ajp: [Arab, [ME], شامي]
-  ajp-arab: [ajp]
-  ajp-latn: [Latn, [ME], šāmi]
+ # The code ajp was deprecated by ISO and merged into apc:
+ # https://iso639-3.sil.org/code/ajp
+  ajp: [apc]
+  ajp-arab: [apc]
+  ajp-latn: [apc-latn]
   ak: [Latn, [AF], Akan]
   akz: [Latn, [AM], Albaamo innaaɬiilka]
   ale: [Latn, [AM, AS], unangam tunuu]
@@ -32,6 +34,9 @@ languages:
   ang: [Latn, [EU], Ænglisc]
   ann: [Latn, [AF], Obolo]
   anp: [Deva, [AS], अंगिका]
+  apc: [Arab, [ME], شامي]
+  apc-arab: [apc]
+  apc-latn: [Latn, [ME], šāmi]
   ar: [Arab, [AF, ME], العربية]
   arc: [Syrc, [ME], ܐܪܡܝܐ]
   arn: [Latn, [AM], mapudungun]