GH actions: Fix vcpkg on macOS

Author: janhenke

.github/workflows/cmake-multi-platform.yml

@@ -73,7 +73,7 @@ jobs:
 
       - name: Setup vcpkg on macOS
         if: runner.os == 'macOS'
-        run: cd vcpkg && ./bootstrap-vcpkg.sh && echo "VCPKG_ROOT=${{ github.workspace }}/vcpkg" >> $GITHUB_ENV
+        run: cd vcpkg && ./bootstrap-vcpkg.sh
 
       - name: Install pkg-config on Windows
         if: runner.os == 'Windows'
@@ -88,7 +88,7 @@ jobs:
           -G 'Ninja'
           -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
           -DCMAKE_MAKE_PROGRAM=ninja
-          -DCMAKE_TOOLCHAIN_FILE="$VCPKG_INSTALLATION_ROOT/scripts/buildsystems/vcpkg.cmake"
+          -DCMAKE_TOOLCHAIN_FILE="${{ github.workspace }}/vcpkg/scripts/buildsystems/vcpkg.cmake"
           -S ${{ github.workspace }}
 
       - name: Configure CMake (Linux)