.github: workflows: bump windows image version

Update windows image from windows-2022 to windows-2025 as this is the
current LTSC version.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

Author: kartben

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04, macos-14, windows-2022]
+        os: [ubuntu-22.04, macos-14, windows-2025]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout