test: the unknown-column twin declines on PG15-17, so the registry says so (#1341)

test_a_named_column_that_does_not_exist_is_refused calls pgcolumnar.analyze(),
which needs PostgreSQL 18, so it declines on 15, 16 and 17 like the other
analyze_function twins. It was missing from expected_unrunnable.txt, so CI's
PG17 cluster job collected and passed 578 and still exited 67 on the
unexpected decline. Measured on PG17: test_analyze_function.py exits 67
without these rows and 0 with them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: jdatcmd

test/pytest/expected_unrunnable.txt

@@ -24,18 +24,21 @@
 # pg_restore_attribute_stats, which core added in PostgreSQL 18.
 15 test_analyze_differential.py::test_analyze_differential
 15 test_analyze_function.py::test_analyze_function
+15 test_analyze_function.py::test_a_named_column_that_does_not_exist_is_refused
 15 test_analyze_function.py::test_histogram_bounds_are_a_positional_stride
 15 test_analyze_function.py::test_null_frac_counts_live_rows_not_ones_a_delete_left
 15 test_analyze_function.py::test_the_documented_statistics_are_the_ones_written
 15 test_analyze_function.py::test_a_covering_projection_does_not_decide_which_columns_get_statistics
 16 test_analyze_differential.py::test_analyze_differential
 16 test_analyze_function.py::test_analyze_function
+16 test_analyze_function.py::test_a_named_column_that_does_not_exist_is_refused
 16 test_analyze_function.py::test_histogram_bounds_are_a_positional_stride
 16 test_analyze_function.py::test_null_frac_counts_live_rows_not_ones_a_delete_left
 16 test_analyze_function.py::test_the_documented_statistics_are_the_ones_written
 16 test_analyze_function.py::test_a_covering_projection_does_not_decide_which_columns_get_statistics
 17 test_analyze_differential.py::test_analyze_differential
 17 test_analyze_function.py::test_analyze_function
+17 test_analyze_function.py::test_a_named_column_that_does_not_exist_is_refused
 17 test_analyze_function.py::test_histogram_bounds_are_a_positional_stride
 17 test_analyze_function.py::test_null_frac_counts_live_rows_not_ones_a_delete_left
 17 test_analyze_function.py::test_the_documented_statistics_are_the_ones_written