chore: use license expression syntax (#64)

Removes deprecated license classifiers, and uses the new license expression and license-files syntax

Fixes #63

Author: cnaples79

LICENSE

@@ -0,0 +1,13 @@
+re2c is distributed with no warranty whatever. The code is certain to contain
+errors. Neither authors nor contributors take any responsibility for the
+consequences of its use.
+
+re2c is in the public domain. Data structures and algorithms used in re2c
+are all either taken from documents available to the general public or are
+inventions of the authors. Programs generated by re2c may be distributed freely.
+re2c itself may be distributed freely, in source or binary, unchanged or
+modified. Distributors may charge whatever fees they can obtain for re2c.
+
+If you do make use of re2c, or incorporate it into a larger project an
+acknowledgement somewhere (documentation, research report, etc.) would be
+appreciated.

pyproject.toml

@@ -6,10 +6,10 @@ build-backend = "scikit_build_core.build"
 name = "re2c"
 description = "re2c is a free and open-source lexer generator for C, C++, D, Go, Haskell, Java, JS, OCaml, Python, Rust, V and Zig with a focus on generating fast code."
 keywords = ["re2c", "build", "c", "c++", "d", "go", "haskell", "java", "js", "ocaml", "python", "rust", "v", "zig"]
-license = {text = "https://github.com/skvadrik/re2c/blob/master/LICENSE"}
+license = "LicenseRef-Public-Domain"
+license-files = ["LICENSE"]
 readme = "README.md"
 classifiers = [
-  "License :: Public Domain",
   "Programming Language :: C",
   "Programming Language :: C++",
   "Programming Language :: D",