add pooch fetch user-agent header

[bjlittle]

🚀 Pull Request

Description

This pull-request injects a User-Agent into the headers of a requests.get issued by pooch.Pooch.fetch when requesting to download an asset.

This is to avoid potential HTTP 403 Forbidden responses from GitHub i.e., RTD servers have unfortunately started to experience this issue for several projects building their documentation.

For further details see readthedocs/readthedocs.org#11763.

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[codecov]

Codecov Report

Attention: Patch coverage is 95.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 91.33%. Comparing base (36ea0db) to head (a9cd38b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/geovista/cache/__init__.py	95.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1202      +/-   ##
==========================================
+ Coverage   91.32%   91.33%   +0.01%     
==========================================
  Files          58       58              
  Lines        2939     2956      +17     
==========================================
+ Hits         2684     2700      +16     
- Misses        255      256       +1     

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