CI: update Python CI targets for macos-x86_64 and macos-arm64

The Python CI jobs for the targets `macos-x86_64` and `macos-arm64` fail systematically with the error:

`This request was automatically failed because there were no enabled runners online to process the request for more than 1 days.`

Here is and example:
 - https://github.com/solvespace/solvespace/actions/runs/12977807252
   - https://github.com/solvespace/solvespace/actions/runs/12977807252/job/36191642761

To fix the problem update the target OS to "macos-latest" for both targets.

As a side note the Python CI uses a huge amount of our "Action budget" - I do not know how much free CI time GitHub currently provides but we should consider this.
https://github.com/solvespace/solvespace/actions/metrics/usage

Author: vespakoen

.github/workflows/python.yml

@@ -82,12 +82,12 @@ jobs:
           #   cibuildwheel_architecture: "ARM64"
           #   cmake_generator_platform: "ARM64"
           - os_arch: "macos-x86_64"
-            os: "macos-11.0"
+            os: "macos-latest"
             os_short: "macos"
             cibuildwheel_architecture: "x86_64"
             architecture: "x86_64"
           - os_arch: "macos-arm64"
-            os: "macos-11.0"
+            os: "macos-latest"
             os_short: "macos"
             cibuildwheel_architecture: "arm64"
             architecture: "arm64"