test: cover protx listdiff platform port restart regression

[thepastaclaw]

Issue being fixed or feature implemented

Adds regression coverage for the protx listdiff restart/snapshot edge case fixed by dashpay#7360.

When an Evo masternode moves from legacy Platform port fields to ExtAddr netInfo, a restarted node may rebuild the deterministic MN diff from serialized state. The regression test verifies that deprecated platformP2PPort / platformHTTPPort fields in protx listdiff remain consistent with the valid Platform addresses instead of reporting 0.

What was done?

Updated test/functional/rpc_netinfo.py to:

• update a pre-v24 EvoNode from legacy Platform ports to ExtAddr Platform addresses after v24 activation
• restart the -deprecatedrpc=service node to exercise the serialized snapshot/diff path
• call protx listdiff over the ProUpServTx block
• assert both addresses and deprecated scalar Platform port fields report the expected non-zero ports

How Has This Been Tested?

Built locally on macOS arm64 with:

./autogen.sh
./configure --without-gui --disable-bench --disable-fuzz-binary
make -j$(sysctl -n hw.ncpu)

Validation:

python3 -m py_compile test/functional/rpc_netinfo.py
git diff --check -- test/functional/rpc_netinfo.py
python3 test/functional/test_runner.py rpc_netinfo.py

rpc_netinfo.py passed.

Pre-PR review gate:

code-review dashpay/dash knst/fix-v24-extdiff test/pr7360-listdiff-regression "Add a functional regression test covering legacy-to-ExtAddr protx listdiff deprecated Platform ports after restart/snapshot"

Result: ship.

Breaking Changes

None. Test-only change.

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)