[appveyor] Add Py 3.11 build

Author: mpsonntag

appveyor.yml

@@ -18,6 +18,10 @@ environment:
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       PYVER: 3
       BITS: 32
+    - PYTHON: "C:\\Python311"
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      PYVER: 3
+      BITS: 32
     - PYTHON: "C:\\Python37-x64"
       PYVER: 3
       BITS: 64
@@ -32,6 +36,10 @@ environment:
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
       PYVER: 3
       BITS: 64
+    - PYTHON: "C:\\Python311-x64"
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      PYVER: 3
+      BITS: 64
 
 init:
   - "ECHO %PYTHON% %vcvars% (%bits%)"