blurb: Drop support for EOL Python 3.7 (#521)

Author: hugovk

README.rst

@@ -25,7 +25,7 @@ and automatically uses the correct file paths.
 
 You can install **blurb** from PyPI using ``pip``.  Alternatively,
 simply add ``blurb`` to a directory on your path.
-**blurb**'s only dependency is Python 3.7+.
+**blurb**'s only dependency is Python 3.8+.
 
 
 Files used by blurb

pyproject.toml

@@ -9,7 +9,7 @@ author-email = "[email protected]"
 maintainer = "Python Core Developers"
 maintainer-email = "[email protected]"
 home-page = "https://github.com/python/core-workflow/tree/main/blurb"
-requires-python = ">=3.7"
+requires-python = ">=3.8"
 description-file = "README.rst"
 classifiers = [
     "Intended Audience :: Developers",