renderer_vk: Fix sample-shading enablement

src/video_core/renderer_vulkan/vk_graphics_pipeline.cpp

@@ -156,6 +156,7 @@ bool GraphicsPipeline::Build(bool fail_on_compile_required) {
     const vk::PipelineMultisampleStateCreateInfo multisampling = {
         .rasterizationSamples = vk::SampleCountFlagBits(info.attachments.sample_count),
         .sampleShadingEnable = true,
+        .minSampleShading = 1.0f,
     };
 
     const vk::PipelineColorBlendAttachmentState colorblend_attachment = {