MNT: Add Python 3.12 to the tests and enable release testing

This adds Python 3.12 to the CI runs and also adds a
CI: build wheels tag that can be added to PRs to build the wheels
for testing.

.github/workflows/ci-testing.yml

@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.9, '3.10', '3.11']
+        python-version: [3.9, '3.10', '3.11', '3.12']
         shapely-dev: [false]
         include:
           - os: ubuntu-latest

.github/workflows/release.yml

@@ -9,6 +9,14 @@ on:
   release:
     types:
       - published
+  # Also allow running this action on PRs if requested by applying the
+  # "Run cibuildwheel" label.
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - labeled
 
 jobs:
   build_sdist:
@@ -49,6 +57,17 @@ jobs:
           if-no-files-found: error
 
   generate-wheels-matrix:
+    if: |
+      github.event_name == 'release' ||
+      (github.event_name == 'pull_request' && (
+        (
+          github.event.action == 'labeled' &&
+          github.event.label.name == 'CI: build wheels'
+        ) ||
+        contains(github.event.pull_request.labels.*.name,
+                'CI: build wheels')
+      )
+      )
     name: Generate wheels matrix
     runs-on: ubuntu-latest
     outputs:

pyproject.toml

@@ -33,6 +33,7 @@ classifiers = [
     'Programming Language :: Python :: 3.9',
     'Programming Language :: Python :: 3.10',
     'Programming Language :: Python :: 3.11',
+    'Programming Language :: Python :: 3.12',
     'Programming Language :: Python :: 3 :: Only',
     'Topic :: Scientific/Engineering',
     'Topic :: Scientific/Engineering :: GIS',