Create a new jsonschema keyword enumCaseInsensitive

[kddejong]

Issue #, if available:
fix #3788

Description of changes:

• Create a new jsonschema keyword enumCaseInsensitive
• Update boto to use enumCaseInsensitive for certain services

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[codecov]

Codecov Report

Attention: Patch coverage is 95.83333% with 1 line in your changes missing coverage. Please review.

Project coverage is 93.78%. Comparing base (74847b1) to head (6b0cde5).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/cfnlint/rules/resources/properties/Enum.py	85.71%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3789      +/-   ##
==========================================
- Coverage   93.79%   93.78%   -0.02%     
==========================================
  Files         363      363              
  Lines       12414    12436      +22     
  Branches     2541     2548       +7     
==========================================
+ Hits        11644    11663      +19     
  Misses        429      429              
- Partials      341      344       +3     

Flag	Coverage Δ
unittests	93.74% <95.83%> (-0.02%)	⬇️

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