Drop Python 3.5 support

The Python 3.5 build is failing because it can't talk to PyPI
(certificate validation failure). I guess it's time to drop it, as it
has been EoL for 3 years.

.github/workflows/tests.yaml

@@ -37,7 +37,7 @@ jobs:
         # When updating the minimum Python version here, also update the
         # `python_requires` from `setup.cfg`.
         # Run on latest minor release of each major python version.
-        python-version: [3.5, 3.6, 3.7, 3.8, 3.9, '3.10', '3.11', '3.12']
+        python-version: [3.6, 3.7, 3.8, 3.9, '3.10', '3.11', '3.12']
         tox-env: ['tests']
 
         include:

pyproject.toml

@@ -2,12 +2,11 @@
 requires = [
     "setuptools >= 44.1.1",
     "wheel >= 0.36.2",
-    "typing >= 3.7.4.3; python_version < '3.5'",
 ]
 build-backend = "setuptools.build_meta"
 
 [tool.black]
-target-version = ['py27', 'py36', 'py37', 'py38']
+target-version = ['py36', 'py37', 'py38']
 
 [tool.towncrier]
 filename = "NEWS.rst"

setup.cfg

@@ -8,8 +8,6 @@ classifiers =
     Intended Audience :: Developers
     License :: OSI Approved :: MIT License
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.4
-    Programming Language :: Python :: 3.5
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
@@ -22,7 +20,6 @@ description = "A small library that versions your Python projects."
 long_description = file: README.rst
 install_requires =
     setuptools
-    typing >= 3.7.4.3; python_version < '3.5'
 
 [options]
 packages = find:

src/incremental/newsfragments/92.removal

@@ -0,0 +1,2 @@
+Support for Python 3.5 has been dropped for lack of test infrastructure.
+