Remove tsickle from @bazel/typescript dependencies.

It's an optional dependency which users can install if they use Closure Compiler
See #323

PiperOrigin-RevId: 221678825

Author: alexeagle

internal/package.json

@@ -16,7 +16,6 @@
   "dependencies": {
     "protobufjs": "5.0.3",
     "source-map-support": "0.5.9",
-    "tsickle": "0.28.0",
     "tsutils": "2.27.2"
   },
   "devDependencies": {