Drop superfluous cmake modules

[yhabteab]

These modules are already provided by CMake itself, so we don't need to ship them by ourselves.

PS: Let's see whether the GAs have something to say about this :).

[Al2Klimov]

TODO

• Raise cmake minimum required version to 3.8...3.17 #10402
• Edit this PR and change the base branch to master, so that commits disappear which belong to Raise cmake minimum required version to 3.8...3.17 #10402

[yhabteab]

Starting with PostgreSQL 9.3, Debian started ¹ to split the PostgreSQL header files including the pg_type.h file into a separate package, which the FindPostgreSQL cmake module ² requires. However, I'm not sure which CMake version introduced it but they accidentally added the PostgreSQL_TYPE_INCLUDE_DIR to the required variables and got fixed later with CMake 3.20. Though, on Debian 11 CMake version 3.18 and on Ubuntu CMake 3.16.3 are installed and contain that accidentally introduced bug, that's why the GHAs are failing. So, we'll have to ship the FindPostgreSQL module for a bit till these OSs get dropped.

Footnotes

1. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=314427 ↩

2. https://github.com/Kitware/CMake/blob/master/Modules/FindPostgreSQL.cmake#L157 ↩

[Al2Klimov]

Ok for GHA = ok for me