ci: Setup back ccache

Author: jorisv

.github/workflows/macos-linux-conda.yml

@@ -97,6 +97,7 @@ jobs:
         cmake .. \
           -G "Ninja" \
           -DCMAKE_INSTALL_PREFIX=$CONDA_PREFIX \
+          -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
           -DPYTHON_EXECUTABLE=$(which python3) \
           -DGENERATE_PYTHON_STUBS=ON \
           -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \

.github/workflows/windows-conda.yml

@@ -70,6 +70,7 @@ jobs:
         cmake ^
           -G "Ninja" ^
           -DCMAKE_INSTALL_PREFIX=%CONDA_PREFIX%\Library ^
+          -DCMAKE_CXX_COMPILER_LAUNCHER=ccache ^
           -DCMAKE_BUILD_TYPE=Release ^
           -DGENERATE_PYTHON_STUBS=ON ^
           -DPYTHON_SITELIB=%CONDA_PREFIX%\Lib\site-packages ^