Update check-release action to v2

[janjagusch]

Releasing a new version with jupyter-releaser currently fails:

dist/quetz_server-0.5.1-py2.py3-none-any.whl: W004: Module is not located at importable path:
  quetz/migrations/versions/0653794b6252_adding_url_and_platforms_dirs.py
  quetz/migrations/versions/0a0ab48887ab_adding_function_args_to_job_spec.py
  quetz/migrations/versions/[302](https://github.com/janjagusch/jupyter_releaser/actions/runs/4185520217/jobs/7252691803#step:5:305)41b33d849_add_task_pending_state.py
  quetz/migrations/versions/[303](https://github.com/janjagusch/jupyter_releaser/actions/runs/4185520217/jobs/7252691803#step:5:306)ff70c27fc_configure_mirror_endpoints.py
  quetz/migrations/versions/3c3288034362_add_channel_metadata.py
  quetz/migrations/versions/53f81aba78ce_use_biginteger_for_size.py
  quetz/migrations/versions/794249a0b1bd_adding_jobs_tables.py
  quetz/migrations/versions/8d1e9a9e0b1f_adding_download_metrics.py
  quetz/migrations/versions/8dfb7c4bfbd7_new_package_versions.py
  quetz/migrations/versions/98c04a65df4a_register_mirrors.py
  quetz/tests/data/dummy-plugin/quetz_dummyplugin/jobs.py

We didn't catch this because we're using an old version of the jupyter-releaser GitHub action.

In this PR, we do three things:

• We bump the jupyter-releaser action to v2
• We ensure that the jupyter-releaser action uses the current branch (and not the default branch)
• We make the check-python step succeed by ignore the W004 check in check-wheel-contents (as recommended for Alembic migration files, details here)

I also added pre-commit and jupyter-releaser as dependencies to the environment file.

[codecov-commenter]

Codecov Report

Base: 82.51% // Head: 82.49% // Decreases project coverage by -0.02% ⚠️

Coverage data is based on head (e98dab6) compared to base (c0e3e2f).
Patch coverage: 87.50% of modified lines in pull request are covered.

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #601      +/-   ##
==========================================
- Coverage   82.51%   82.49%   -0.02%     
==========================================
  Files          78       78              
  Lines        6063     6068       +5     
==========================================
+ Hits         5003     5006       +3     
- Misses       1060     1062       +2     

Impacted Files	Coverage Δ
quetz/db_models.py	95.78% <75.00%> (-1.12%)	⬇️
quetz/dao.py	89.16% <100.00%> (ø)
quetz/migrations/env.py	69.44% <100.00%> (ø)

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[janjagusch]

Instead of moving the Alembic migration files outside the package, we should ignore the check-wheel-contents error (see here for details). Moving the tests outside the package seems reasonable, though.