Termux allows dynamically enabling or disabling the entire Software vulkan ICDs at once
via 'pkg install/remove mesa-vulkan-icd-swrast/swiftshader', and when they are uninstalled,
they become invisible to libplacebo, so it will just be more convenient and less confusing for Termux
users if libplacebo is forced to use (and report that it's using) software rendering anytime it's
available.

--- a/src/vulkan/context.c
+++ b/src/vulkan/context.c
@@ -1463,7 +1463,7 @@ pl_vulkan pl_vulkan_create(pl_log log, const struct pl_vulkan_params *params)
             .get_proc_addr  = params->get_proc_addr,
             .surface        = params->surface,
             .device_name    = params->device_name,
-            .allow_software = params->allow_software,
+            .allow_software = true,
         };
         memcpy(dparams.device_uuid, params->device_uuid, VK_UUID_SIZE);