fix: decimal of arbeth:tbill

TICKET: COIN-3916

Author: kamleshmugdiya

modules/statics/src/coins.ts

@@ -2496,7 +2496,7 @@ export const coins = CoinMap.fromCoins([
     '1a5481b2-67c1-4872-9b81-478773cc10c6',
     'arbeth:tbill',
     'OpenEden T-Bills',
-    18,
+    6,
     '0xf84d28a8d28292842dd73d1c5f99476a80b6666a',
     UnderlyingAsset['arbeth:tbill'],
     AccountCoin.DEFAULT_FEATURES_EXCLUDE_SINGAPORE

modules/statics/src/coins/ofcCoins.ts

@@ -793,7 +793,7 @@ export const ofcCoins = [
     '1ba44303-cdf1-4322-bb82-54adbbbbd7f0',
     'ofcarbeth:tbill',
     'OpenEden T-Bills',
-    18,
+    6,
     UnderlyingAsset['arbeth:tbill']
   ),
   ofcArbethErc20('5be753ec-179f-4bad-8552-b3190b723779', 'ofcarbeth:xai', 'Xai', 18, UnderlyingAsset['arbeth:xai']),