Another fix for CI

Surely if I keep making commits that say "another fix" eventually I'll
run out of fixes. Surely, right? I'd put this in limerick form to be
more amusing if someone comes to read this but I'm not clever enough to
do that, so instead I'll just abruptly

.github/workflows/main.yml

@@ -178,7 +178,8 @@ jobs:
             -DCMAKE_C_COMPILER=/usr/lib/llvm-18/bin/clang \
             -DCMAKE_SYSTEM_NAME=WASI \
             -DWASI_SDK_INCLUDE_TESTS=ON \
-            -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=OFF
+            -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=OFF \
+            -DCMAKE_CXX_LINKER_DEPFILE_SUPPORTED=OFF
       - run: ninja -C build
       - run: ctest --output-on-failure --parallel 10 --test-dir build/tests
 

cmake/wasi-sdk-sysroot.cmake

@@ -52,7 +52,8 @@ set(default_cmake_args
   # is just a bare "clang" installation then it can mistakenly deduce that this
   # feature is supported when it's not actually supported for WASI targets.
   # Currently `wasm-ld` does not support the linker flag for this.
-  -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=OFF)
+  -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=OFF
+  -DCMAKE_CXX_LINKER_DEPFILE_SUPPORTED=OFF)
 
 if(CMAKE_C_COMPILER_LAUNCHER)
   list(APPEND default_cmake_args -DCMAKE_C_COMPILER_LAUNCHER=${CMAKE_C_COMPILER_LAUNCHER})