Flat map all the things

In an earlier commit, entity-manager gained required dependency
on std::flat_map.  This means that EM can only compile with gcc-15,
which the project only recently moved to.  Rather than move backwards,
port forward all uses of boost flat_map and flat_set to their std
equivalents.

Tested: entity-manager launches and enumerates devices on
gb200-obmc.

Change-Id: Id24803057711c60d5b00f436db80b27edbb756a3
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/test/test_fru-utils.cpp b/test/test_fru-utils.cpp
index f925db2..684159d 100644
--- a/test/test_fru-utils.cpp
+++ b/test/test_fru-utils.cpp
@@ -464,7 +464,7 @@
         0x35, 0x30, 0xc0, 0xc4, 0x76, 0x30, 0x2e, 0x31, 0xc1, 0x00, 0x00, 0x00,
         0x00, 0x00, 0x00, 0xb4, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
-    boost::container::flat_map<std::string, std::string> result;
+    std::flat_map<std::string, std::string, std::less<>> result;
     ASSERT_EQ(formatIPMIFRU(bmcFru, result), resCodes::resOK);
 
     EXPECT_THAT(
@@ -641,7 +641,7 @@
     std::vector<uint8_t> assembledData;
     EXPECT_TRUE(assembleFruData(assembledData, areasData));
 
-    boost::container::flat_map<std::string, std::string> result;
+    std::flat_map<std::string, std::string, std::less<>> result;
     auto rescode = formatIPMIFRU(assembledData, result);
     EXPECT_NE(rescode, resCodes::resErr);