Update Dockerfile.master.template: fetch libcgal-dev 5.5.1 from Debian testing in order to build SCFGAL 1.4.1

[swiss-knight]

• Set SFCGAL git hash equals to version tag 1.4.1 from Oslandia's repository,
• Specifically fetch libcgal-dev from Debian testing (sid) to be able to install SFCGAL 1.4.x,
• Clean out commented code.

This should fix:

• 3D function errors due to bug in sfcgal #333

• Installing postgis_sfcgal extension version >= 1.4, ideally based on the latest stable CGAL release (5.5.1) #335

• TODO: I would say it could be worth to programmatically set the SFCGAL tag in the same way than the PROJ or GEOS ones when updating the versioned images. Or even to build CGAL itself from sources prior to SCFGAL?

---

This is the full postgis version string when I currently build the image using the proposed PR on 15-master:

POSTGIS="3.4.0dev 3.3.0rc2-390-gc2a0b2024"
  [EXTENSION]
      PGSQL="150"
      GEOS="3.12.0dev-CAPI-1.18.0"
      SFCGAL="SFCGAL 1.4.1, CGAL 5.5.1, BOOST 1.74.0" # <--- updated!
      PROJ="9.2.0"
      LIBXML="2.9.10"
      LIBJSON="0.15"
      LIBPROTOBUF="1.3.3"
      WAGYU="0.5.0 (Internal)"
      TOPOLOGY