GHA CI: link to C libraries dynamically

The C libraries is now updated by the OS and therefore  there is no
reason to bundle static versions which might be outdated later.
Also enable Control Flow Guard for 3rd party libraries.

.github/workflows/ci_windows.yaml

@@ -22,6 +22,7 @@ jobs:
     env:
       boost_path: "${{ github.workspace }}/../boost"
       libtorrent_path: "${{ github.workspace }}/libtorrent"
+      vpkg_triplet_path: "${{ github.workspace }}/../triplets_overlay"
 
     steps:
       - name: Checkout repository
@@ -42,29 +43,32 @@ jobs:
           vcpkgDirectory: C:/vcpkg
           doNotUpdateVcpkg: true  # the preinstalled vcpkg is updated regularly
 
-      - name: Install dependencies from vcpkg
+      - name: Install dependencies with vcpkg
         run: |
-          # tell vcpkg to only build Release variants of the dependencies
+          # create our own triplet
           New-Item `
-            -Path "${{ github.workspace }}" `
-            -Name "triplets_overlay" `
-            -ItemType Directory
-          Copy-Item `
-            "${{ env.RUNVCPKG_VCPKG_ROOT }}/triplets/x64-windows-static.cmake" `
-            "${{ github.workspace }}/triplets_overlay/x64-windows-static-release.cmake"
+            -Force `
+            -ItemType File `
+            -Path "${{ env.vpkg_triplet_path }}/x64-windows-static-md-release.cmake"
           Add-Content `
-            "${{ github.workspace }}/triplets_overlay/x64-windows-static-release.cmake" `
-            -Value "set(VCPKG_BUILD_TYPE release)"
+            -Path "${{ env.vpkg_triplet_path }}/x64-windows-static-md-release.cmake" `
+            -Value @("set(VCPKG_TARGET_ARCHITECTURE x64)",
+              "set(VCPKG_LIBRARY_LINKAGE static)",
+              "set(VCPKG_CRT_LINKAGE dynamic)",
+              "set(VCPKG_BUILD_TYPE release)",
+              "set(VCPKG_C_FLAGS /guard:cf)",
+              "set(VCPKG_CXX_FLAGS /guard:cf)",
+              "set(VCPKG_LINKER_FLAGS /guard:cf)")
           # clear buildtrees after each package installation to reduce disk space requirements
           $packages = `
-            "openssl:x64-windows-static-release",
-            "zlib:x64-windows-static-release"
+            "openssl:x64-windows-static-md-release",
+            "zlib:x64-windows-static-md-release"
           ${{ env.RUNVCPKG_VCPKG_ROOT }}/vcpkg.exe upgrade `
-            --overlay-triplets="${{ github.workspace }}/triplets_overlay" `
-            --no-dry-run
+            --no-dry-run `
+            --overlay-triplets="${{ env.vpkg_triplet_path }}"
           ${{ env.RUNVCPKG_VCPKG_ROOT }}/vcpkg.exe install `
-            --overlay-triplets="${{ github.workspace }}/triplets_overlay" `
             --clean-after-build `
+            --overlay-triplets="${{ env.vpkg_triplet_path }}" `
             $packages
 
       - name: Install boost
@@ -104,7 +108,7 @@ jobs:
             -DBUILD_SHARED_LIBS=OFF `
             -Ddeprecated-functions=OFF `
             -Dstatic_runtime=OFF `
-            -DVCPKG_TARGET_TRIPLET=x64-windows-static-release
+            -DVCPKG_TARGET_TRIPLET=x64-windows-static-md-release
           cmake --build build
           cmake --install build
 
@@ -122,7 +126,7 @@ jobs:
             -DMSVC_RUNTIME_DYNAMIC=ON `
             -DQT6=ON `
             -DTESTING=ON `
-            -DVCPKG_TARGET_TRIPLET=x64-windows-static-release `
+            -DVCPKG_TARGET_TRIPLET=x64-windows-static-md-release `
             -DVERBOSE_CONFIGURE=ON `
             --graphviz=build/target_graph.dot
           cmake --build build --target qbt_update_translations