Codechange: [CI] manually install vcpkg for all targets (#12241)

From macos-14, vcpkg is no longer installed on the runner-image.
It stands to reason that this will also roll out to new images
for other OSes. To be pre-emptive about it, start using our own
cloned vcpkg for all targets.

.github/workflows/release-windows.yml

@@ -53,6 +53,11 @@ jobs:
           core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
           core.exportVariable('VCPKG_BINARY_SOURCES', 'clear;x-gha,readwrite')
 
+    - name: Install vcpkg
+      run: |
+        git clone https://github.com/microsoft/vcpkg
+        .\vcpkg\bootstrap-vcpkg.bat -disableMetrics
+
     - name: Install dependencies
       shell: bash
       run: |
@@ -121,7 +126,7 @@ jobs:
         cmake ${GITHUB_WORKSPACE} \
           -GNinja \
           -DVCPKG_TARGET_TRIPLET=${{ matrix.arch }}-windows-static \
-          -DCMAKE_TOOLCHAIN_FILE="c:\vcpkg\scripts\buildsystems\vcpkg.cmake" \
+          -DCMAKE_TOOLCHAIN_FILE="${GITHUB_WORKSPACE}\vcpkg\scripts\buildsystems\vcpkg.cmake" \
           -DOPTION_USE_NSIS=ON \
           -DHOST_BINARY_DIR=${GITHUB_WORKSPACE}/build-host \
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
@@ -147,7 +152,7 @@ jobs:
         cmake ${GITHUB_WORKSPACE} \
           -GNinja \
           -DVCPKG_TARGET_TRIPLET=${{ matrix.arch }}-windows-static \
-          -DCMAKE_TOOLCHAIN_FILE="c:\vcpkg\scripts\buildsystems\vcpkg.cmake" \
+          -DCMAKE_TOOLCHAIN_FILE="${GITHUB_WORKSPACE}\vcpkg\scripts\buildsystems\vcpkg.cmake" \
           -DHOST_BINARY_DIR=${GITHUB_WORKSPACE}/build-host \
           -DCMAKE_BUILD_TYPE=RelWithDebInfo \
           -DOPTION_SURVEY_KEY=${{ inputs.survey_key }} \