Use an SPDX license

Author: gvalkov

pyproject.toml

@@ -8,7 +8,7 @@ version = "1.9.2"
 description = "Bindings to the Linux input handling subsystem"
 keywords = ["evdev", "input", "uinput"]
 readme = "README.md"
-license = {file = "LICENSE"}
+license = "BSD-3-Clause"
 requires-python = ">=3.8"
 authors = [
   { name="Georgi Valkov", email="georgi.t.valkov@gmail.com" },