commit 978c7809923b3ef62a39ab404f35093ea39fcdc7
author Jagpal Singh Gill <paligill@gmail.com> Wed Oct 29 11:44:14 2025 -0700
committer Jagpal Singh Gill <paligill@gmail.com> Wed Oct 29 11:44:14 2025 -0700
tree e03cc4afb340024f7675d862a735839b1c2ae0d8
parent cad9ecf69472f03f9ece64eff5d2d94bc51bcf90

common: use std::flat_map for entity_manager

Use std::flat_map instead of boost flat_map to avoid extra dependency on
boost as std::flat_map is available.

Tested:
Verified the EntityManager interface works as expected after change as
configuration interfaces gets processed by Modbus RTU service.
```
root@ventura:~# busctl tree xyz.openbmc_project.ModbusRTU
`- /xyz
  `- /xyz/openbmc_project
    `- /xyz/openbmc_project/inventory_source
      |- /xyz/openbmc_project/inventory_source/Heat_Exchanger_12_DevTTYUSB0
      |- /xyz/openbmc_project/inventory_source/Heat_Exchanger_12_DevTTYUSB1
      |- /xyz/openbmc_project/inventory_source/Reservoir_Pumping_Unit_12_DevTTYUSB0
      `- /xyz/openbmc_project/inventory_source/Reservoir_Pumping_Unit_12_DevTTYUSB1
root@ventura:~# busctl tree xyz.openbmc_project.EntityManager
`- /xyz
  `- /xyz/openbmc_project
    |- /xyz/openbmc_project/EntityManager
    `- /xyz/openbmc_project/inventory
      `- /xyz/openbmc_project/inventory/system
        |- /xyz/openbmc_project/inventory/system/board
        | `- /xyz/openbmc_project/inventory/system/board/Ventura_Modbus
        |   |- /xyz/openbmc_project/inventory/system/board/Ventura_Modbus/DevTTYUSB0
        |   |- /xyz/openbmc_project/inventory/system/board/Ventura_Modbus/DevTTYUSB1
        |   |- /xyz/openbmc_project/inventory/system/board/Ventura_Modbus/Heat_Exchanger
        |   `- /xyz/openbmc_project/inventory/system/board/Ventura_Modbus/Reservoir_Pumping_Unit
        `- /xyz/openbmc_project/inventory/system/chassis
          |- /xyz/openbmc_project/inventory/system/chassis/Heat_Exchanger_12_DevTTYUSB0
          |- /xyz/openbmc_project/inventory/system/chassis/Heat_Exchanger_12_DevTTYUSB1
          |- /xyz/openbmc_project/inventory/system/chassis/Reservoir_Pumping_Unit_12_DevTTYUSB0
          | `- /xyz/openbmc_project/inventory/system/chassis/Reservoir_Pumping_Unit_12_DevTTYUSB0/Reservoir_Pumping_Unit_12_DevTTYUSB0
          `- /xyz/openbmc_project/inventory/system/chassis/Reservoir_Pumping_Unit_12_DevTTYUSB1
            `- /xyz/openbmc_project/inventory/system/chassis/Reservoir_Pumping_Unit_12_DevTTYUSB1/Reservoir_Pumping_Unit_12_DevTTYUSB1
```

Change-Id: Iecb61359a0f9259bfec0f0678f13217928be67d6
Signed-off-by: Jagpal Singh Gill <paligill@gmail.com>