ci: enable -Werror=dev

Turn developer & deprecation warnings into errors.

.github/workflows/ci.yml

@@ -223,7 +223,7 @@ jobs:
 
       - name: Generate build system
         run: |
-          cmake -B build --preset vs2022 -DCMAKE_TOOLCHAIN_FILE="${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" ${{ matrix.generate-options }}
+          cmake -B build -Werror=dev --preset vs2022 -DCMAKE_TOOLCHAIN_FILE="${VCPKG_INSTALLATION_ROOT}/scripts/buildsystems/vcpkg.cmake" ${{ matrix.generate-options }}
 
       - name: Save vcpkg binary cache
         uses: actions/cache/save@v4