vd_lavc: always load VO interops with non-copy hw decoders

For METHOD_INTERNAL hwdecs (non-copy cases), make sure the VO interops
are always loaded, because those decoders will output hardware pixel
formats, which will need special support in vo_gpu. Otherwise,
initialization will fail, complaining that it can't convert the output
format to something the VO supports.

video/decode/vd_lavc.c

@@ -471,6 +471,10 @@ static void select_and_set_hwdec(struct dec_video *vd)
                     }
                     MP_WARN(vd, "Using emulated hardware decoding API.\n");
                 }
+            } else if (!hwdec->copying) {
+                // Most likely METHOD_INTERNAL, which often use delay-loaded
+                // VO support as well.
+                hwdec_devices_request_all(vd->hwdec_devs);
             }
 
             ctx->use_hwdec = true;