COMP: Bump to minimum CMake 3.16.3

[jhlegarreta]

Bump to minimum CMake 3.16.3: use same cmake_minimum_required values as ITK.

Bumped in ITK in commit
InsightSoftwareConsortium/ITK@b01b325

Fixes:

-- cmake_minimum_required of 3.10.2 is not enough.
CMake Warning at D:/a/ITKLabelErodeDilate/ITK/CMake/ITKModuleExternal.cmake:15 (message):
  cmake_minimum_required must be at least 3.16.3
Call Stack (most recent call first):
  CMakeLists.txt:7 (include)

raised for example in:
https://open.cdash.org/builds/10184812/configure

[jhlegarreta]

Build failures are unrelated.

[dzenanz]

We should bump it to 3.22.1 eventually.

[jhlegarreta]

X-ref: InsightSoftwareConsortium/ITK#4761

[jhlegarreta]

X-ref InsightSoftwareConsortium/ITK#4761

We should bump it to 3.22.1 eventually.

I think it is becoming clear that time should be invested in having ways to maintain remotes easily, especially when it comes to applying changes that are relevant to all remotes. Otherwise, these efforts are not sustainable. X-ref: InsightSoftwareConsortium/ITK#5134 (comment), InsightSoftwareConsortium/ITK#4786

[jhlegarreta]

Re #41 (comment) Another reason for that:
https://github.com/InsightSoftwareConsortium/ITKThinShellDemons/blob/main/pyproject.toml#L37

Python 3.8 is at EOL. All remotes should be updated, and their minor (major?) versions be updated, tags/releases created in git.