Change of Vertical Unit - EPSG:1069 [DEPRECATED] 🢡 EPSG:1104

[mwtoews]

While tidying up docs, I've noted that EPSG:1069 is deprecated in favour of EPSG:1104, effective 31 March 2021, with these change notes.

I'm unsure of the implications of this change, as they appear to be subtle. Is this just a matter of replacing some EPSG:1069 codes? This code is widely used throughout PROJ:

$ git grep "\b1069\b"

[rouault]

It has already been mostly taken into account in f6abb7d75. I'm not sure we need to follow up more than that. PROJ still uses the deprecated method with the explicit conversion factor in the createOperations() code when creating transformation pipelines. It makes our life easier to use it, so I'm not super enthusiastic about changing that just for the sake of not using a deprecated EPSG method, that isn't broken by itself.