fix: add dependency on GSL for span

Until we can bump the C++ version to have a native `<span>`, this'll do.

Author: zao

CMakeLists.txt

@@ -113,6 +113,7 @@ find_package(fmt CONFIG REQUIRED)
 find_package(glfw3 CONFIG REQUIRED)
 find_package(gli CONFIG REQUIRED)
 find_package(LuaJIT REQUIRED)
+find_package(Microsoft.GSL CONFIG REQUIRED)
 find_package(PkgConfig REQUIRED)
 find_package(re2 CONFIG REQUIRED)
 find_package(sol2 CONFIG REQUIRED)
@@ -210,6 +211,7 @@ target_link_libraries(SimpleGraphic
     glm::glm
     imgui
     LuaJIT::LuaJIT
+    Microsoft.GSL::GSL
     PkgConfig::libjxl
     PkgConfig::libjxl_threads
     re2::re2

vcpkg.json

@@ -9,6 +9,7 @@
     "gli",
     "libjxl",
     "luajit",
+    "ms-gsl",
     "pkgconf",
     "re2",
     "sol2",