Feedback fixes

[Choochmeque]

Description

Fixed docs generation
Fixed build from local source if available
Added check to make sure rust version follows c++ version

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.

🌦️ >> Documentation << 🌦️
https://sites.ecmwf.int/docs/dev-section/eckit/pull-requests/PR-329

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.62%. Comparing base (da7bb69) to head (15c6d08).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #329   +/-   ##
========================================
  Coverage    67.61%   67.62%           
========================================
  Files         1182     1182           
  Lines        61697    61697           
  Branches      4667     4667           
========================================
+ Hits         41718    41720    +2     
+ Misses       19979    19977    -2     

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