sql/export: skip columns with Bit(0) type in parquet test

We were seeing failures on this randomized test when these
columns were generated. The testutils parquet decoder can't
handle this type (added in #132944) so these fail, but it
doesn't represent a real issue.

This fix skips these the randomly generated test cases that
include this column type.

Fixes: #154011
Epic: none

Release note: None

Author: aerfrei

pkg/sql/importer/exportparquet_test.go

@@ -229,6 +229,22 @@ func TestRandomParquetExports(t *testing.T) {
 					require.NoError(t, err)
 
 					for _, col := range cols {
+						// Skip tables with BIT(0) columns (or arrays of BIT(0)).
+						// The testutils parquet decoder cannot decode these as
+						// into the expected empty bit array and decodes the as
+						// nil. Ignore these to avoid these flakes.
+						colTyp := col.Typ
+						if colTyp.Family() == types.ArrayFamily {
+							colTyp = colTyp.ArrayContents()
+						}
+						if colTyp.Family() == types.BitFamily && colTyp.Width() == 0 {
+							// We skip these because of the aforementioned
+							// decoder issue.
+							t.Logf("skipping table '%s' because it has BIT(0) column '%s' (type: %s)",
+								tableName, col.Name, colTyp.String())
+							return fmt.Errorf("table has BIT(0) column")
+						}
+
 						// TODO(#104278): don't call this function to check if a type is supported.
 						// We should explicitly use the ones supported by  util/parquet).
 						_, err := parquet.NewSchema([]string{"test"}, []*types.T{col.Typ})