Fix syntax of license declaration

Author: ctrueden

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "scyjava"
 version = "1.10.3.dev0"
 description = "Supercharged Java access from Python"
-license = "Unlicense"
+license = {text = "Unlicense"}
 authors = [{name = "SciJava developers", email = "ctrueden@wisc.edu"}]
 readme = "README.md"
 keywords = ["java", "maven", "cross-language"]