Remove project_url column from osm.pgosm_flex

[rustprooflabs]

Details

I'm noticing this as I'm looking at other improvements to the osm.pgosm_flex table (#293, #295). When this meta table was initially created there was no "update" mode, so this table really was only expected to have 1 row.

That is changing, and even with re-running create mode, having the URL in there seems silly. Planning to remove with next set of breaking changes.

SELECT *
    FROM osm.pgosm_flex
;

id|imported                     |osm_date  |default_date|region                               |pgosm_flex_version|srid|project_url                                |osm2pgsql_version|language|osm2pgsql_mode|
--+-----------------------------+----------+------------+-------------------------------------+------------------+----+-------------------------------------------+-----------------+--------+--------------+
 1|2023-01-21 09:25:57.844 -0700|2023-01-21|false       |north-america/us-district-of-columbia|0.7.0.rc.1-ed5a95a|3857|https://github.com/rustprooflabs/pgosm-flex|1.7.2            |        |create        |
 2|2023-01-21 09:32:43.328 -0700|2023-01-21|false       |north-america/us-district-of-columbia|0.7.0.rc.1-ed5a95a|3857|https://github.com/rustprooflabs/pgosm-flex|1.7.2            |        |create        |
 3|2023-01-21 09:38:52.483 -0700|2023-01-21|false       |north-america/us-district-of-columbia|0.7.0.rc.1-ed5a95a|3857|https://github.com/rustprooflabs/pgosm-flex|1.7.2            |        |create        |