[Bug][Arista]: snmp/test_snmp_phy_entity.py::test_snmp_phy_entity::test_fan_info fails with KeyError: 'position_in_parent'

[arista-nwolfe]

Issue Description

snmp/test_snmp_phy_entity.py::test_snmp_phy_entity::test_fan_info iterates through all FAN_INFO| entries in STATE_DB, this include fans connected to the fabric modules.
e.g. ['FAN_INFO|fan3/7', 'FAN_INFO|fan2/1', 'FAN_INFO|fan1/4', 'FAN_INFO|fan1/2', 'FAN_INFO|fan5/1', 'FAN_INFO|fan4/3', ...]
It then looks up each fan in the PHYSICAL_ENTITY_INFO| to get the parent modules:
e.g.

root@cmp227:~# sonic-db-cli STATE_DB hgetall "PHYSICAL_ENTITY_INFO|fan5/1"
{'position_in_parent': '1', 'parent_name': 'Module 7'}

It then expects the parent_name to also be in PHYSICAL_ENTITY_INFO| in STATE_DB but the fabric modules aren't in STATE_DB:

sonic-db-cli STATE_DB keys \* | grep -i "PHYSICAL_ENTITY_INFO|Module"

https://github.com/sonic-net/sonic-mgmt/blob/202405/tests/snmp/test_snmp_phy_entity.py#L301

Results you see

Fabric fan parent entity not present in PHYSICAL_ENTITY_INFO| in STATE_DB.

Results you expected to see

Either fabric modules should be included in PHYSICAL_ENTITY_INFO| in STATE_DB or we should skip testing fabric fans.

Is it platform specific

generic

Relevant log output

No response

Output of show version

No response

Attach files (if any)

No response

[yxieca]

@arlakshm please triage.