Resolve skipped tests: Needs COLLATE and pg_table_is_visible

[amotl]

Introduction

Another patch added a few more tests using the relaxed dialects together with pandas.

• Add software tests using pandas #31

Problem

A few test cases are skipped by "Needs COLLATE and pg_table_is_visible".

• test_psycopg_to_sql
• test_psycopg_async_to_sql
• test_asyncpg_to_sql

References

• Add pg_table_is_visible scalar, for Django and psql compatibility crate/crate#7988

[amotl]

The pg_table_is_visible function became available in the 5.8 release.