Increasing `carState.cumLagMs` on master

Describe the bug

Re-posting per discussions from Discord:

Seeing carState.cumLagMs doing this linear increase after our recent upstream syncs, also see this in some stock openpilot routes. Is this expected moving forward?

Stock openpilot routes:

• https://connect.comma.ai/424b2a6c1b69a3bc/0000006c--00a1917b4c/660/720
• https://connect.comma.ai/424b2a6c1b69a3bc/00000059--5e422f076c/5076/5094

Seems to be coming from https://github.com/commaai/openpilot/pull/38464. Once this commit is reverted, carState.cumLagMs is no longer increasing.

Some users are reporting LKAS error from lagging.

Provide a route where the issue occurs

424b2a6c1b69a3bc/0000006c--00a1917b4c

openpilot version

master

Additional info

No response