Hildebrand Glow is using deprecated varables

[AndySymons]

Describe the bug
Home assistant gives warnings that deprecated variables are being used, so this integration will not be available next year.

To Reproduce
Reload the system and check the logs

Expected behaviour
There should be no warnings, so we can be confident that Hildebrand Glow will continue working in future.

Version
24.02.1

General log
`Logger: homeassistant.components.sensor
Source: helpers/deprecation.py:205
Integration: Sensor (documentation, issues)
First occurred: 10:45:31 (8 occurrences)
Last logged: 10:45:31

DEVICE_CLASS_ENERGY was used from hildebrandglow_dcc, this is a deprecated constant which will be removed in HA Core 2025.1. Use SensorDeviceClass.ENERGY instead, please create a bug report at https://github.com/HandyHat/ha-hildebrandglow-dcc/issues
DEVICE_CLASS_MONETARY was used from hildebrandglow_dcc, this is a deprecated constant which will be removed in HA Core 2025.1. Use SensorDeviceClass.MONETARY instead, please create a bug report at https://github.com/HandyHat/ha-hildebrandglow-dcc/issues
STATE_CLASS_MEASUREMENT was used from hildebrandglow_dcc, this is a deprecated constant which will be removed in HA Core 2025.1. Use SensorStateClass.MEASUREMENT instead, please create a bug report at https://github.com/HandyHat/ha-hildebrandglow-dcc/issues
STATE_CLASS_TOTAL_INCREASING was used from hildebrandglow_dcc, this is a deprecated constant which will be removed in HA Core 2025.1. Use SensorStateClass.TOTAL_INCREASING instead, please create a bug report at https://github.com/HandyHat/ha-hildebrandglow-dcc/issues
Logger: homeassistant.const
Source: helpers/deprecation.py:205
First occurred: 10:45:31 (1 occurrences)
Last logged: 10:45:31

ENERGY_KILO_WATT_HOUR was used from hildebrandglow_dcc, this is a deprecated constant which will be removed in HA Core 2025.1. Use UnitOfEnergy.KILO_WATT_HOUR instead, please create a bug report at https://github.com/HandyHat/ha-hildebrandglow-dcc/issues`