Remove Minor from our extension scripts

[robe]

This will be for PostGIS 3.3.0 moving forward. We discussed the idea of doing that for all minors, but decided that was too drastic.

So sadly we've still got to carry all those scripts.

3.3 will have scripts

# these all 0 byte
 postgis--3.0
 :
 postgis--3.1.0 --3.3.X.sql 
 postgis--3.1.1 --3.3.X.sql
 postgis--3.1.2 --3.3.X.sql
:
:
postgis--3.2.1 --3.3.X.sql

# these not 0 byte
postgis--3.3.X--3.3.sql (not 0 byte)
postgis-3.3next--3.3.sql (not 0 byte)  
postgis-3.3next-3.3.sql (not 0 byte)

(the 3.3next 3.3.sql I am thinking if we decided we want our alter extension scripts to have CREATE OR REPLACE only for existing and CREATE for net-net new, we'd still keep the CREATE OR REPLACE for the 3.3next even for net-net new and for the 3.3X--3.3.sql this would be CREATE for net-net new functionality.

and so most we will use 0 byte files as Paul proposed here - ​https://trac.osgeo.org/postgis/wiki/PostGISExtensionPaths#SOLUTION3

postgis 3.4 would then look like

# these all 0 byte
 postgis--3.0
 :
 postgis--3.1.0 --3.4.X.sql 
 postgis--3.1.1 --3.4.X.sql
 postgis--3.1.2 --3.4.X.sql
:
:
postgis--3.2.1 --3.4.X.sql
postgis--3.3 --3.4.X.sql #regardless which 3.3 micro release, no new files

# these not 0 byte
postgis--3.4.X--3.4.sql (not 0 byte)
postgis-3.4next--3.4.sql (not 0 byte)  
postgis-3.4-3.4next.sql (not 0 byte)