prefer std::format over fmt

Switch to std::format to remove the dependency on fmt.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Id3a1295ba8a90fb756cfc500892dcc5b3235e27b
diff --git a/occ_presence.cpp b/occ_presence.cpp
index a8a5115..73ccf66 100644
--- a/occ_presence.cpp
+++ b/occ_presence.cpp
@@ -46,7 +46,7 @@
     auto occsPresent = std::stoi(data, nullptr, 0);
     if (manager.getNumOCCs() != occsPresent)
     {
-        log<level::ERR>(fmt::format("OCC presence mismatch - BMC: {}, OCC: {}",
+        log<level::ERR>(std::format("OCC presence mismatch - BMC: {}, OCC: {}",
                                     manager.getNumOCCs(), occsPresent)
                             .c_str());
         if (callBack)