Do not use eckit Grid.spec for gridspecs

[sandorkertesz]

Description

In the experimental geography code using eckit.geo.Grid.spec is disabled since it does not seem to work in the version used.

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.36%. Comparing base (a5a18c3) to head (c694e86).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #891      +/-   ##
===========================================
+ Coverage    85.35%   85.36%   +0.01%     
===========================================
  Files          184      184              
  Lines        14562    14573      +11     
  Branches       732      732              
===========================================
+ Hits         12429    12440      +11     
  Misses        1922     1922              
  Partials       211      211              

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