[Nexthop] Define TAJO_SDK for cmake builds with SAI_TAJO_IMPL

[raghavv-nexthop]

Pre-submission checklist

• I've ran the linters locally and fixed lint errors related to the files I modified in this PR. You can install the linters by running pip install -r requirements-dev.txt && pre-commit install
• pre-commit run

Summary

Issue

The AgentAclTableGroupTrafficTest.VerifyDscpMarkingAndTtlAclTable agent_hw test would fail this equality check:

/src/fboss/agent/test/agent_hw_tests/AgentAclTableGroupTrafficTests.cpp:363: Failure
Expected equality of these values:
  dscpAclPkts - beforeAclPkts.first
    Which is: 0
  (1 * 2 * 2 * (utility::kUdpPorts().size() + utility::kTcpPorts().size()))
    Which is: 40

Cause

The OSS cmake build never defined the TAJO_SDK macro, which fbcode supplies from its tp2 SAI config. FBOSS uses that macro to gate Tajo-specific SAI attribute mappings, so cmake-built binaries were compiling the generic (non-Tajo) code paths on Tajo hardware.

The visible symptom was AgentAclTableGroupTrafficTest.VerifyDscpMarkingAndTtlAclTable failing on wedge800cact: SaiAclTableManager advertised SAI_ACL_TABLE_ATTR_FIELD_IPV6_NEXT_HEADER in the ACL table's key profile while the entries only set IP_PROTOCOL_NUMBER. That mismatch meant the marking entries never matched: traffic flowed, but ACL hit counters read 0.

Solution

This adds add_definitions (-DTAJO_SDK) to the SAI_TAJO_IMPL block, mirroring the existing CHENAB_SAI_SDK handling in the same file.

Test Plan

After incorporating this change, I ran the test on a Wedge800cact unit using this command:

./run_test.py sai_agent --config ./hw_test_configs/wedge800cact.agent.materialized_JSON --skip-known-bad-tests leaba/25.11.4210/25.11.4210/graphene202x --enable-production-features g202x --agent-run-mode=multi_switch --filter=*AgentAclTableGroupTrafficTest.VerifyDscpMarkingAndTtlAclTable*

which produced these results:

[ PASSED ] cold_boot.AgentAclTableGroupTrafficTest.VerifyDscpMarkingAndTtlAclTable (20390 ms)
[ PASSED ] warm_boot.AgentAclTableGroupTrafficTest.VerifyDscpMarkingAndTtlAclTable (8717 ms)
Summary:
   PASSED : 2
   FAILED : 0
   SKIPPED : 0
   TIMEOUT : 0