Autogen: Restore <target_name>_autogen_timestamp_deps target

Revert commit 91b2ce4a69 (Autogen: Remove ..._autogen_timestamp_deps
target, 2024-06-27, v3.31.0-rc1~391^2).  The `_autogen_timestamp_deps`
target is needed for pre-`AUTOGEN_BETTER_GRAPH_MULTI_CONFIG` behavior.

Issue: #26080
Issue: #26475
1 file changed