glm5next: use ggml_prec_set_acc for the indexer weights

ggml_mul_mat_set_prec was deprecated upstream in ggml-org#26675 and the macOS
prebuilt legs build with fatal warnings, so the mix stopped compiling
there. Same op_params slot, same F32 accumulation.

Author: danielhanchen

src/models/glm5next.cpp

@@ -409,7 +409,7 @@ ggml_tensor * llama_model_glm5next::graph::build_indexer(
 
     // sign-unconstrained head weights; PREC_F32 is load-bearing, bf16 swaps near-tied pools
     ggml_tensor * w = ggml_mul_mat(ctx0, layer.indexer_proj, cur);
-    ggml_mul_mat_set_prec(w, GGML_PREC_F32);
+    ggml_prec_set_acc(w, GGML_PREC_F32);
     w = ggml_reshape_4d(ctx0, w, n_ihead, n_tps, 1, n_stream);
     w = ggml_scale(ctx0, w, 1.0f/sqrtf(float(d_idx*n_ihead)));
     cb(w, "indexer_weights", il);