Add no_git=True when possible

[mirpedrol]

As mentioned in #1688 comment

I think in the case of nf-core lint you could actually pass no_git=True to PipelineCreate here, and skip making a git repository entirely, as the linter does not seem to require a git repository to compare the template files

The argument no_git=True can be added when a pipeline is created but there's no need to initialise a git repository.

PR checklist

• This comment contains a description of changes (with reason)
• CHANGELOG.md is updated
• If you've fixed a bug or added code that should be tested, add tests!
• Documentation in docs is updated

[codecov]

Codecov Report

Merging #1709 (3bf6d70) into dev (880d627) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #1709   +/-   ##
=======================================
  Coverage   68.23%   68.23%           
=======================================
  Files          57       57           
  Lines        6744     6744           
=======================================
  Hits         4602     4602           
  Misses       2142     2142           

Impacted Files	Coverage Δ
nf_core/lint/files_unchanged.py	72.61% <ø> (ø)

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[ErikDanielsson]

We should do the same in tests/test_lint.py, tests/test_utils.py and tests/test_modules.py also right?

[mirpedrol]

Thanks @ErikDanielsson, I forgot some tests!
I don't add it to tests/test_lint.py as the git repository is required there.

[ErikDanielsson]

Looks good now!