Bump upper supported python version to 3.12

Changes upper python version of test matrix to 3.12.

Also changes macos test runner from 'latest' to 'macos-13'
whilst awaiting wheels from pytables for Mac M1.

.github/workflows/build-test.yml

@@ -25,8 +25,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ["3.9", "3.11"]
+        os: [ubuntu-latest, macos-13, windows-latest]
+        python-version: ["3.9", "3.12"]
 
     steps:
       - uses: actions/checkout@v4

pyproject.toml

@@ -44,6 +44,7 @@ classifiers = [
 	"Programming Language :: Python :: 3.9",
 	"Programming Language :: Python :: 3.10",
 	"Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
 	"Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Education",
     "Topic :: Office/Business :: Financial",
@@ -98,4 +99,4 @@ write_to = "src/market_prices/_version.py"
 
 [tool.black]
 line-length = 88
-target-version = ['py39', 'py310', 'py311']
+target-version = ['py39', 'py310', 'py311', 'py312']