Drop support for Proj < 6.1 and PG 11 in PostGIS 3.4

[robe]

We voted on both and motion passed.

Drop PostgreSQL 11: ​https://lists.osgeo.org/pipermail/postgis-devel/2022-September/029792.html

Drop Proj < 6.1: ​https://lists.osgeo.org/pipermail/postgis-devel/2022-September/029793.html

[Regina Obe <lr@…>]

In 3e38e0b/git:

Remove support for PostgreSQL < 12
Remove support for Proj < 6.1
Closes #5229 for PostGIS 3.4.0

[robe]

seem to have broken PG15 somehow

[robe]

oh wait I don't think this is my change. This is change in upstream, since it's been failing with this since 9/1. ​https://debbie.postgis.net/view/PostgreSQL/job/PostGIS_Regress_PGDEV_Weekly/19717/consoleFull and my local PG15 is regressing cleanly.

 GEOS config:          /var/lib/jenkins/workspace/geos/rel-3.8w64/bin/geos-config
  GEOS version:         3.8.3dev
  GDAL config:          /var/lib/jenkins/workspace/gdal/rel-3.2w64/bin/gdal-config
  GDAL version:         3.2.3
  SFCGAL config:        /usr/bin/sfcgal-config
  SFCGAL version:       1.3.8
  PostgreSQL config:    /var/lib/jenkins/workspace/pg/rel/pg15w64/bin/pg_config
  PostgreSQL version:   PostgreSQL 15beta3
  PROJ4 version:        72
  Libxml2 config:       /usr/bin/xml2-config
  Libxml2 version:      2.9.14
  JSON-C support:       yes
  protobuf support:     yes
  protobuf-c version:   1003003
  PCRE support:         not found
  Perl:                 /usr/bin/perl

but I do need to change gitlab ci and drone ci.

[Regina Obe <lr@…>]

In be6b2ba/git:

Upgrade dronie and gitlab runs to use PG > 11 and newer images that should have newer proj
Closes #5230 for PostGIS 3.4.0
Closes #5229 for PostGIS 3.4.0

[Regina Obe <lr@…>]

In 8d482e2/git:

Fix debbie's make dist. Needs to be > PG 11. References #5229 for PostGIS 3.4.0