compose/compare: disable DO blocks

We just saw a stack overflow due to an infinite recursion when evaluating
top-level DO block which has an inner DO block and some loops. I couldn't
reproduce the failure, but this test doesn't make it easy (e.g. it
doesn't log CREATE TABLE stmts), so we'll just disable DO blocks
specifically for this test, hoping that other tests will reproduce the
issue.

Release note: None

Author: yuzefovich

pkg/compose/compare/compare/compare_test.go

@@ -80,7 +80,7 @@ func TestCompare(t *testing.T) {
 	configs := map[string]testConfig{
 		"mutators": {
 			setup:           sqlsmith.Setups[sqlsmith.RandTableSetupName],
-			opts:            []sqlsmith.SmitherOption{sqlsmith.CompareMode()},
+			opts:            []sqlsmith.SmitherOption{sqlsmith.CompareMode(), sqlsmith.DisableDoBlocks()},
 			ignoreSQLErrors: true,
 			conns: []testConn{
 				{