Add missing template args list after the use of the template keyword

Since llvm/llvm-project#80801, clang requires an
explicit template list after the use of the template keyword for
template member function.

Author: FMarno

include/nop/rpc/interface.h

@@ -244,7 +244,7 @@ struct InterfaceMethod {
     template <typename Sender>
     static void Invoke(Sender* sender, Status<Return>* return_value,
                        Args... args) {
-      sender->template SendMethod(InterfaceMethod::Selector, return_value,
+      sender->template SendMethod<>(InterfaceMethod::Selector, return_value,
                                   std::forward_as_tuple(args...));
     }
 

include/nop/types/variant.h

@@ -238,7 +238,7 @@ class Variant {
   // resulting type.
   template <typename... Args>
   void Construct(Args&&... args) {
-    index_ = value_.template Construct(std::forward<Args>(args)...);
+    index_ = value_.template Construct<>(std::forward<Args>(args)...);
   }
   void Construct(EmptyVariant) {}
 
@@ -255,14 +255,14 @@ class Variant {
   // multiple element types.
   template <typename T, typename U>
   void Assign(TypeTag<T>, U&& value) {
-    if (!value_.template Assign(TypeTag<T>{}, index_, std::forward<U>(value))) {
+    if (!value_.template Assign<>(TypeTag<T>{}, index_, std::forward<U>(value))) {
       Destruct();
       Construct(TypeTag<T>{}, std::forward<U>(value));
     }
   }
   template <typename T>
   void Assign(T&& value) {
-    if (!value_.template Assign(index_, std::forward<T>(value))) {
+    if (!value_.template Assign<>(index_, std::forward<T>(value))) {
       Destruct();
       Construct(std::forward<T>(value));
     }