fix LICENSE reference

Author: Roman

pyproject.toml

@@ -4,7 +4,7 @@ version = "1.0.0"
 description = "Asyncio library for interacting with substrate. Mostly API-compatible with py-substrate-interface"
 readme = "README.md"
 requires-python = ">=3.9,<3.13"
-license = { file = "LICENSE.txt" }
+license = { file = "LICENSE" }
 keywords = ["substrate", "development", "bittensor"]
 authors = [
   { name = "Opentensor Foundation" },