How to drop all of a table's indices

create or replace function drop_indexes_on_table(a_schema text, a_table text)
returns int
language 'plpgsql'
as $$
    sql_to_run text;
    idx_rec record;
    num_idxs_dropped int;
    num_idxs_dropped := 0;

    raise notice 'looking for indexes for table %.%', a_schema, a_table;

    for idx_rec in
    select idx_info.relname as index_name
      from pg_index as idx
      join pg_class as tbl
        on tbl.oid = idx.indrelid
      join pg_namespace as schm
        on tbl.relnamespace = schm.oid
      join pg_class as idx_info
        on idx.indexrelid = idx_info.oid
     where schm.nspname = a_schema
       and tbl.relname = a_table
        num_idxs_dropped := num_idxs_dropped + 1;
        raise notice 'about to drop index % for table %.%', idx_rec.index_name, a_schema, a_table;
        sql_to_run := 'drop index if exists ' || a_schema || '.' || idx_rec.index_name;
        execute sql_to_run;
    end loop;
    return num_idxs_dropped;