Fix CI: remove invalid 'dxc' brew formula and drop hard FSR3 runtime dependency

macOS: 'dxc' is not a valid Homebrew formula — the failing brew install line
was aborting early, preventing SDL2 and other packages from being installed.
Removed 'dxc' from the brew install command.

Linux arm64 / Windows: the add_dependencies(wowee wowee_fsr3_official_runtime_copy)
forced the FSR3 Kits build (including VK permutation generation) into every
normal cmake --build invocation. This broke arm64 (no DXC binary available) and
Windows MSYS2 (bash script ran in wrong shell context, exit 127). The FSR3 Path A
runtime is now a strictly opt-in artifact — build it explicitly with:
  cmake --build build --target wowee_fsr3_official_runtime_copy
The main wowee binary still loads it dynamically at runtime when present and
falls back gracefully when it is not.

.github/workflows/build.yml

@@ -138,7 +138,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          brew install cmake pkg-config sdl2 glew glm openssl@3 zlib ffmpeg unicorn dxc \
+          brew install cmake pkg-config sdl2 glew glm openssl@3 zlib ffmpeg unicorn \
             stormlib vulkan-loader vulkan-headers shaderc dylibbundler || true
           # dylibbundler may not be in all brew mirrors; install separately to not block others
           brew install dylibbundler 2>/dev/null || true

CMakeLists.txt

@@ -757,8 +757,10 @@ if(TARGET wowee_fsr3_framegen_amd_vk_probe)
     target_link_libraries(wowee PRIVATE wowee_fsr3_framegen_amd_vk_probe)
 endif()
 if(TARGET wowee_fsr3_official_runtime_copy)
-    # Ensure Path A runtime is available in bin/ whenever wowee is built.
-    add_dependencies(wowee wowee_fsr3_official_runtime_copy)
+    # FSR3 Path A runtime is an opt-in artifact; build explicitly with:
+    #   cmake --build build --target wowee_fsr3_official_runtime_copy
+    # Do NOT add as a hard dependency of wowee — it would break arm64 and Windows CI
+    # (no DXC available on arm64; bash context issues on MSYS2 Windows).
 endif()
 
 # Link Unicorn if available