fix(tamil-old): set ligatures to true in tamil old (@Leonabcd123) (monkeytypegame#7349)

### Description

Closes monkeytypegame#7347

Author: Leonabcd123

frontend/static/languages/tamil_old.json

@@ -1,7 +1,7 @@
 {
   "name": "tamil_old",
   "rightToLeft": false,
-  "ligatures": false,
+  "ligatures": true,
   "bcp47": "ta",
   "words": [
     "அஞ்சல்",