Replace deprecated classifier with licence expression (PEP 639)

Author: hugovk

.ci/install.sh

@@ -50,7 +50,7 @@ if [[ $(uname) != CYGWIN* ]]; then
     # Pyroma uses non-isolated build and fails with old setuptools
     if [[ $GHA_PYTHON_VERSION == 3.9 ]]; then
         # To match pyproject.toml
-        python3 -m pip install "setuptools>=67.8"
+        python3 -m pip install "setuptools>=77"
     fi
 
     # webp

pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 build-backend = "backend"
 requires = [
-  "setuptools>=67.8",
+  "setuptools>=77",
 ]
 backend-path = [
   "_custom_build",
@@ -14,14 +14,14 @@ readme = "README.md"
 keywords = [
   "Imaging",
 ]
-license = { text = "MIT-CMU" }
+license = "MIT-CMU"
+license-files = [ "LICENSE" ]
 authors = [
   { name = "Jeffrey A. Clark", email = "aclark@aclark.net" },
 ]
 requires-python = ">=3.9"
 classifiers = [
   "Development Status :: 6 - Mature",
-  "License :: OSI Approved :: CMU License (MIT-CMU)",
   "Programming Language :: Python :: 3 :: Only",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",