COMP: Build against ITK main; repair ExternalData, baselines, and docs CI #883

Job	Run time
build-test-cxx (windows-2022)	20m 7s
build-test-python-superbuild (windows-2022)	28s
build-test-notebooks (ubuntu-24.04)	1m 36s
build-test-notebooks (windows-2022)	1m 40s
build-test-documentation (ubuntu-24.04)	7m 7s
build-test-python-superbuild (macos-15)	27s
build-test-python-superbuild (ubuntu-24.04)	23s
build-test-cxx (macos-14)	17m 3s
build-test-cxx (ubuntu-24.04)	22m 11s
build-test-notebooks (macos-14)	1m 47s
	1h 12m 49s

Provide feedback