Use vcpkg from submodule instead

Author: fredemmott

.github/workflows/ci.yml

@@ -53,7 +53,8 @@ jobs:
             --config ${{matrix.config}} `
             --parallel `
             -- `
-            /p:CL_MPCount=
+            /p:CL_MPCount= `
+          -DVCPKG_TARGET_TRIPLET=x64-windows-static
           $version="$(Get-Content version.txt)"
           Add-Content $Env:GITHUB_OUTPUT "VERSION=${version}"
       - name: Install debug symbols

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "third-party/vcpkg"]
+	path = third-party/vcpkg
+	url = https://github.com/microsoft/vcpkg.git

CMakeLists.txt

@@ -55,15 +55,9 @@ if ("${VCPKG_TARGET_TRIPLET}" MATCHES "-static$")
   add_link_options("${COMMON_LINK_OPTIONS}")
 endif()
 
-if ("$ENV{VCPKG_ROOT}")
-  set(VCPKG_ROOT "$ENV{VCPKG_ROOT}")
-else()
-  set(VCPKG_ROOT "$ENV{VCPKG_INSTALLATION_ROOT}")
-endif()
-
 set(
   CMAKE_TOOLCHAIN_FILE
-  "${VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake"
+  "${CMAKE_SOURCE_DIR}/third-party/vcpkg/scripts/buildsystems/vcpkg.cmake"
   CACHE STRING "Vcpkg toolchain file"
 )