Remove git fetch calls from jobs

[0xnm]

What does this PR do?

Removing git fetch calls from the jobs, because they are not needed - main branch is not needed during the build and proper revision is checked out by the runner anyway.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.11%. Comparing base (a4adc10) to head (b9db8a0).
Report is 5 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop     #319   +/-   ##
==========================================
  Coverage      78.11%   78.11%           
  Complexity       261      261           
==========================================
  Files             31       31           
  Lines            941      941           
  Branches         113      113           
==========================================
  Hits             735      735           
  Misses           151      151           
  Partials          55       55           

see 2 files with indirect coverage changes