gpu: Fixed uninitialized variable in SDL_AcquireGPUCommandBuffer().

Fixes #13191.

(cherry picked from commit 190afc0f4fd584028bbdba2f6d2c12c40c2825a6)

src/gpu/SDL_gpu.c

@@ -1573,6 +1573,7 @@ SDL_GPUCommandBuffer *SDL_AcquireGPUCommandBuffer(
         commandBufferHeader->copy_pass.in_progress = false;
         commandBufferHeader->swapchain_texture_acquired = false;
         commandBufferHeader->submitted = false;
+        commandBufferHeader->ignore_render_pass_texture_validation = false;
         SDL_zeroa(commandBufferHeader->render_pass.vertex_sampler_bound);
         SDL_zeroa(commandBufferHeader->render_pass.vertex_storage_texture_bound);
         SDL_zeroa(commandBufferHeader->render_pass.vertex_storage_buffer_bound);