fix(license): correction to MIT + MIT-0 (no proprietary anymore) (#1883)

Author: meckhardt

Diff for: pyproject.toml

@@ -7,7 +7,7 @@ include = ["aws_lambda_powertools/py.typed", "THIRD-PARTY-LICENSES"]
 classifiers=[
     "Development Status :: 5 - Production/Stable",
     "Intended Audience :: Developers",
-    "License :: OSI Approved :: MIT License",
+    "License :: OSI Approved :: MIT No Attribution License (MIT-0)",
     "Natural Language :: English",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
@@ -16,7 +16,9 @@ classifiers=[
 repository="https://github.com/awslabs/aws-lambda-powertools-python"
 readme = "README.md"
 keywords = ["aws_lambda_powertools", "aws", "tracing", "logging", "lambda", "powertools", "feature_flags", "idempotency", "middleware"]
-license = "MIT-0"
+# MIT-0 is not recognized as an existing license from poetry.
+# By using `MIT` as a license value, a `License :: OSI Approved :: MIT License` classifier is added to the classifiers list.
+license = "MIT"
 
 [tool.poetry.dependencies]
 python = "^3.7.4"