Allow adjusting ports used for CTest testing (#331) #290

Job	Run time
freebsd12 (CMake) (LLVM)	54s
freebsd12 (CMake) (LLVM)	13m 25s
freebsd13 (CMake) (LLVM)	16m 8s
freebsd13 (CMake) (LLVM)	16m 8s
macos-11 (CMake) (LLVM)	6m 20s
macos-11 (CMake) (LLVM)	6m 20s
macos-12 (CMake) (LLVM)	5m 14s
macos-12 (CMake) (LLVM)	5m 14s
macos-13 (Autotools) (LLVM)	6m 36s
macos-13 (Autotools) (LLVM)	6m 36s
centos:7 (CMake) (GNU)	4m 48s
centos:7 (CMake) (GNU)	4m 48s
macos-13 (CMake) (LLVM)	4m 48s
macos-13 (CMake) (LLVM)	4m 48s
debian:11 (CMake) (GNU)	3m 8s
debian:11 (CMake) (GNU)	3m 8s
debian:12 (CMake) (GNU)	2m 8s
debian:12 (CMake) (GNU)	2m 8s
debian:testing (CMake) (GNU)	2m 44s
debian:testing (CMake) (GNU)	2m 44s
fedora:37 (CMake) (GNU)	3m 9s
fedora:37 (CMake) (GNU)	3m 9s
fedora:38 (CMake) (GNU)	3m 17s
fedora:38 (CMake) (GNU)	3m 17s
fedora:rawhide (CMake) (GNU)	4m 12s
fedora:rawhide (CMake) (GNU)	4m 12s
ubuntu:20.04 (CMake) (GNU)	2m 0s
ubuntu:20.04 (CMake) (GNU)	2m 0s
ubuntu:22.04 (Autotools) (GNU)	2m 57s
ubuntu:22.04 (Autotools) (GNU)	2m 57s
ubuntu:22.04 (Autotools) (LLVM)	2m 25s
ubuntu:22.04 (Autotools) (LLVM)	2m 25s
ubuntu:22.04 (CMake) (GNU)	2m 35s
ubuntu:22.04 (CMake) (GNU)	2m 35s
ubuntu:22.04 (CMake) (LLVM)	2m 22s
ubuntu:22.04 (CMake) (LLVM)	2m 22s
debian:12 (CMake) (GNU) (Latest Mapnik)	2m 40s
debian:12 (CMake) (GNU) (Latest Mapnik)	2m 40s
ubuntu:22.04 (CMake) (GNU) (Latest Mapnik)	3m 0s
ubuntu:22.04 (CMake) (GNU) (Latest Mapnik)	3m 0s
	2h 55m 21s

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