Remove unused std::string variables to fix -Wunused-variable warnings.

PiperOrigin-RevId: 1002723432

Author: CEL Dev Team

eval/compiler/resolver.cc

@@ -196,8 +196,8 @@ std::vector<cel::FunctionRegistry::LazyOverload> Resolver::FindLazyOverloads(
   auto prefixes = GetPrefixesFor(name);
   for (const auto& prefix : prefixes) {
     std::string qualified_name = absl::StrCat(prefix, name);
-    funcs = function_registry_.FindLazyOverloadsByArity(name, receiver_style,
-                                                        arity);
+    funcs = function_registry_.FindLazyOverloadsByArity(qualified_name,
+                                                        receiver_style, arity);
     if (!funcs.empty()) {
       return funcs;
     }

eval/eval/function_step.cc

@@ -192,7 +192,6 @@ Value NoOverloadResult(absl::string_view name,
 
   // If no errors or unknowns in input args, create new CelError for missing
   // overload.
-  std::string signature;
   if (receiver_style) {
     if (args.empty()) {
       // Should not be possible, but return a sensible error in case of logic