support drop triggers (#527)

Seems like all we have to do is enable it

Co-authored-by: Glauber Costa <[email protected]>

Author: Glauber Costa

sqld/src/query_analysis.rs

@@ -85,6 +85,7 @@ impl StmtKind {
             Cmd::Stmt(Stmt::AlterTable(tbl_name, _)) => write_if_not_reserved(tbl_name),
             Cmd::Stmt(
                 Stmt::DropIndex { .. }
+                | Stmt::DropTrigger { .. }
                 | Stmt::CreateTrigger {
                     temporary: false, ..
                 }