radv: Disable predication for subpass and image clears.

According to the Vulkan spec 21.4 "Conditional Rendering", only clearing attachments with vkCmdClearAttachments is subject to conditional rendering.

Subpass clear and CmdClearColorImage / CmdClearDepthStencilImage should always be executed even if it happens in a conditional rendering block.

Missing CTS coverage is tracked here:

• https://gitlab.khronos.org/Tracker/vk-gl-cts/-/issues/3710
• https://gitlab.khronos.org/Tracker/vk-gl-cts/-/issues/3714