use std::format instead of fmt::format

The std::format is sufficient for the uses in this repository except
for in one file (override_fan_target.cpp, since P2286 isn't supported
by GCC yet).  Switch to std::format whenever possible.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib2576fb530a4d7ce238e1b0bd95b40b476ec2107
diff --git a/control/json/triggers/timer.cpp b/control/json/triggers/timer.cpp
index ce8bba7..2036042 100644
--- a/control/json/triggers/timer.cpp
+++ b/control/json/triggers/timer.cpp
@@ -19,12 +19,11 @@
 #include "group.hpp"
 #include "trigger_aliases.hpp"
 
-#include <fmt/format.h>
-
 #include <nlohmann/json.hpp>
 #include <phosphor-logging/log.hpp>
 
 #include <chrono>
+#include <format>
 
 namespace phosphor::fan::control::json::trigger::timer
 {
@@ -52,7 +51,7 @@
     else
     {
         log<level::ERR>(
-            fmt::format("Timer trigger type '{}' is not supported", type)
+            std::format("Timer trigger type '{}' is not supported", type)
                 .c_str(),
             entry("AVAILABLE_TYPES={oneshot, repeating}"));
         throw std::runtime_error("Unsupported timer trigger type given");