bump: update version to 3.8.post0.dev14 and adjust OS

Updates the project version in `pyproject.toml` to3.8.post0.dev14 to reflect the latest development 
iteration. Modifies the OS matrix in the GitHub Actions 
workflow to remove macOS 15, streamlining the build 
process for supported operating systems.

Author: steffengraber

.github/workflows/build_nest_wheel.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-13, macos-14, macos-15, ubuntu-24.04]        
+        os: [macos-13, macos-14, ubuntu-24.04]        
     steps:
       - uses: actions/checkout@v4
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "scikit_build_core.build"
 
 [project]
 name = "nest-simulator"
-version = "3.8.post0.dev13"
+version = "3.8.post0.dev14"
 description = "NEST is a simulator for spiking neural network models that focuses on the dynamics, size and structure of neural systems rather than on the exact morphology of individual neurons."
 keywords = ["nest", "simulator", "neuroscience", "neural", "neuron", "network", "ai", "spike", "spiking"]
 readme = "README.md"