Remove Eigen3 minimum version requirement in CMake

[ptahmose]

Description

Previously, CMakeLists.txt required Eigen3 version 3.3 or higher. Now, it will accept any available version of Eigen3 found. However - with version 5, there was a version mismatch required. This now removes the version requirement, proper operation with latest version 5 was checked for.
This is a build-system-only change.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

locally

Checklist:

• I followed the Contributing Guidelines.
• I did a self-review.
• I commented my code, particularly in hard-to-understand areas.
• I updated the documentation.
• I updated the version of libCZI following Versioning of libCZI depending on the type of change
  • Bug fix -> PATCH
  • New feature -> MINOR
  • Breaking change -> MAJOR
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.38%. Comparing base (4746709) to head (a34e9d6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #163   +/-   ##
=======================================
  Coverage   66.38%   66.38%           
=======================================
  Files          96       96           
  Lines       12365    12365           
=======================================
  Hits         8209     8209           
  Misses       4156     4156           

Flag	Coverage Δ
windows-latest	66.38% <ø> (ø)

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