docs/conf: remove hashbang

[pjonsson]

This file is never executed, so
remove the hashbang.

---

📚 Documentation preview 📚: https://datacube-explorer--672.org.readthedocs.build/en/672/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.56%. Comparing base (7d933f4) to head (69b23de).
Report is 55 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #672      +/-   ##
===========================================
+ Coverage    89.26%   89.56%   +0.29%     
===========================================
  Files           34       34              
  Lines         4119     4217      +98     
===========================================
+ Hits          3677     3777     +100     
+ Misses         442      440       -2     

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[omad]

This file is never directly executed, so I'd prefer to remove this line, and it doesn't need to be executable. It's probably an artefact of an old version of sphinx-quickstart.

conf.py in the official sphinx docs doesn't include one.

[pjonsson]

This file is never directly executed, so I'd prefer to remove this line

Even better, fixed!