Rename Okinawan

The previous name was added in 2008 for translatewiki, and it's
not actually the autonym, but its IPA pronunciation.

This language uses several orthographies based
on Japanese writing systems, and several linguists
whose expertise is Ryukyuan linguistics recommended
that I use this Hiragana-based name as the most
neutral and understandable. I'll also add aliases
to ULS to ensure that it's findable.

Also remove the "Kana" writing system,
which is just a subset of "Jpan".

data/langdb.yaml

@@ -539,7 +539,7 @@ languages:
   rw: [Latn, [AF], Kinyarwanda]
  # Bug: 60815
   rwr: [Deva, [AS], मारवाड़ी]
-  ryu: [Kana, [AS], ʔucināguci]
+  ryu: [Jpan, [AS], うちなーぐち]
   sa: [Deva, [AS], संस्कृतम्]
   sah: [Cyrl, [EU, AS], саха тыла]
   sat: [Olck, [AS], ᱥᱟᱱᱛᱟᱲᱤ]
@@ -744,7 +744,7 @@ scriptgroups:
  # the Brahmic family.
   SouthAsian: [Beng, Cakm, Deva, Gujr, Guru, Knda, Mlym, Mtei, Olck, Orya, Rohg, Saur, Sinh, Sylo, Taml, Telu, Tibt, Thaa, Wara]
   Cyrillic: [Cyrl]
-  CJK: [Hani, Hans, Hant, Kana, Kore, Jpan, Yiii]
+  CJK: [Hani, Hans, Hant, Kore, Jpan, Yiii]
   SouthEastAsian: [Bali, Batk, Bugi, Java, Khmr, Laoo, Lana, Mymr, Thai]
   Mongolian: [Mong]
   SignWriting: [Sgnw]

data/language-data.json

@@ -3488,11 +3488,11 @@
             "मारवाड़ी"
         ],
         "ryu": [
-            "Kana",
+            "Jpan",
             [
                 "AS"
             ],
-            "ʔucināguci"
+            "うちなーぐち"
         ],
         "sa": [
             "Deva",
@@ -4647,7 +4647,6 @@
             "Hani",
             "Hans",
             "Hant",
-            "Kana",
             "Kore",
             "Jpan",
             "Yiii"