[glsl] fix clang 23 build error for unused function `SetDefinition` (#4389)

Reported by @gixel

> unused function template SetDefinition  in: src/shader_recompiler/backend/glsl/emit_glsl.cpp:32:6: error: unused function template 'SetDefinition' [-Werror,-Wunused-template]

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4389
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Maufeat <sahyno1996@gmail.com>

src/shader_recompiler/backend/glsl/emit_glsl.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -28,11 +31,6 @@ struct FuncTraits<ReturnType_ (*)(Args...)> {
     using ArgType = std::tuple_element_t<I, std::tuple<Args...>>;
 };
 
-template <auto func, typename... Args>
-void SetDefinition(EmitContext& ctx, IR::Inst* inst, Args... args) {
-    inst->SetDefinition<Id>(func(ctx, std::forward<Args>(args)...));
-}
-
 template <typename ArgType>
 auto Arg(EmitContext& ctx, const IR::Value& arg) {
     if constexpr (std::is_same_v<ArgType, std::string_view>) {
@@ -53,21 +51,10 @@ auto Arg(EmitContext& ctx, const IR::Value& arg) {
 template <auto func, bool is_first_arg_inst, size_t... I>
 void Invoke(EmitContext& ctx, IR::Inst* inst, std::index_sequence<I...>) {
     using Traits = FuncTraits<decltype(func)>;
-    if constexpr (std::is_same_v<typename Traits::ReturnType, Id>) {
-        if constexpr (is_first_arg_inst) {
-            SetDefinition<func>(
-                ctx, inst, *inst,
-                Arg<typename Traits::template ArgType<I + 2>>(ctx, inst->Arg(I))...);
-        } else {
-            SetDefinition<func>(
-                ctx, inst, Arg<typename Traits::template ArgType<I + 1>>(ctx, inst->Arg(I))...);
-        }
+    if constexpr (is_first_arg_inst) {
+        func(ctx, *inst, Arg<typename Traits::template ArgType<I + 2>>(ctx, inst->Arg(I))...);
     } else {
-        if constexpr (is_first_arg_inst) {
-            func(ctx, *inst, Arg<typename Traits::template ArgType<I + 2>>(ctx, inst->Arg(I))...);
-        } else {
-            func(ctx, Arg<typename Traits::template ArgType<I + 1>>(ctx, inst->Arg(I))...);
-        }
+        func(ctx, Arg<typename Traits::template ArgType<I + 1>>(ctx, inst->Arg(I))...);
     }
 }