Disable HIDAPI libusb support on FreeBSD in CI

It looks like we're expecting a newer version of libusb than is installed on our VM image. Disabling pending further investigation.
diff --git a/.github/workflows/vmactions.yml b/.github/workflows/vmactions.yml
index f701c8d..e24f9d0 100644
--- a/.github/workflows/vmactions.yml
+++ b/.github/workflows/vmactions.yml
@@ -52,6 +52,7 @@
           cmake -S . -B build -GNinja \
             -Wdeprecated -Wdev -Werror \
             -DCMAKE_BUILD_TYPE=Release \
+            -DSDL_HIDAPI_LIBUSB=OFF \
             -DSDL_CHECK_REQUIRED_INCLUDES="/usr/local/include" \
             -DSDL_CHECK_REQUIRED_LINK_OPTIONS="-L/usr/local/lib"
           cmake --build build/ --config Release --verbose -- -j`sysctl -n hw.ncpu`