tests: register the last baseline entry, so the unreferenced-test sweep is zero-tolerance (Fixes #2018)

CMakeLists.txt

@@ -311,6 +311,11 @@ add_python_test(ci_targets_self ${CMAKE_SOURCE_DIR}/tools/ci/ci_targets_check.py
 # baseline records a test as never-run, which for a passing test is the wrong outcome -- so it is registered and the line
 # is removed, which is the shrink the baseline's own comment asks for.
 add_python_test(moe_expert_chunks_accum_test ${CMAKE_SOURCE_DIR}/tests/moe_expert_chunks_accum_test.py)
+# engine#2018: the last baseline entry. The file recorded it as "needs the benchmark harness", but the test stubs
+# llama-bench (stdlib only: hashlib/importlib.util/json/pathlib/platform/sys) and passes on a plain interpreter, so it is a
+# test with no runner rather than a test that cannot run here. Registered, and the baseline is now empty: from here the
+# sweep is zero-tolerance instead of a record of known gaps.
+add_python_test(hyperloom_benchmark_test ${CMAKE_SOURCE_DIR}/tests/hyperloom_benchmark_test.py)
 # engine#1820: the other half of ci_targets_check -- a standalone shell test that nothing references cannot fail.
 # `need` is every tests/*.sh, `have` is every file that mentions its basename somewhere that can run it, and
 # tools/ci/unreferenced_tests.txt carries the deliberate exclusions WITH their reasons, so the list can shrink.

tools/ci/unreferenced_py_tests.txt

@@ -24,13 +24,12 @@
 # A SET baseline, not an allow-list: `tools/ci/tests_referenced_check.py` FAILS when a name appears here that is not in
 # the tree's current set, and REPORTS a line whose file is registered now, so this can only shrink.
 #
-# The number is 1 (was 2: moe_expert_chunks_accum_test.py is portable and passing, so it is registered rather than
-# baselined -- engine#2018), and getting it right took a correction worth recording: the first version of the rule scanned
+# The number is 0. Both original entries were portable tests with no runner, not tests that cannot run here, so both are
+# registered (moe_expert_chunks_accum_test.py, then hyperloom_benchmark_test.py -- engine#2018), and getting it right took a correction worth recording: the first version of the rule scanned
 # `RUNNERS`, which contains one FILE (CMakeLists.txt) and two directories, and tested `is_dir()` on all three -- so every
 # `add_python_test(...)` registration in CMakeLists.txt was invisible and 35 of 42 tests looked unregistered. The arm
 # "a cleared baseline entry is reported" caught it: registering a test in CMakeLists.txt did not clear its line. The true
 # figure was 2 of 42, which is a healthy tree; the rule is here to keep it that way rather than to record a backlog.
 #
 # Each line is a real test whose runner was never added; the fix per file is one `add_python_test(...)`.
 #
-tests/hyperloom_benchmark_test.py