Fix sdist tarball including unnecessary files

[djhoese]

As discussed on slack, I discovered that hatch/hatchling does not use the MANIFEST.in template file for what to include in an sdist. As such, it seems we have been including all files in the git repository when run in CI. Fortunately since this is from a fresh clone this was mostly only including a few extra files plus all the documentation source files, benchmark files, etc. Hatchling always includes READMEs and LICENSE files.

In this PR I've removed the unused MANIFEST.in file and make a custom section in pyproject.toml to explicitly say what files to include. Normally this would be packages = ["satpy"] but to preserve what the manifest file had I also included authors, changelog, security, and citation. The one major difference I've configured here is to NOT include the documentation. I can be convinced otherwise, but I just don't think they are necessary.

The wheel file is unchanged and only includes the python package source.

• Closes #xxxx
• Tests added
• Fully documented
• Add your name to AUTHORS.md if not there already

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.11%. Comparing base (0b9760c) to head (b1b587c).
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3030      +/-   ##
==========================================
- Coverage   96.12%   96.11%   -0.02%     
==========================================
  Files         383      383              
  Lines       55577    55577              
==========================================
- Hits        53424    53416       -8     
- Misses       2153     2161       +8     

Flag	Coverage Δ
behaviourtests	3.91% <ø> (ø)
unittests	96.20% <ø> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[coveralls]

Pull Request Test Coverage Report for Build 12772053752

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 8 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.01%) to 96.217%

---

Files with Coverage Reduction	New Missed Lines	%
satpy/tests/utils.py	2	93.16%
satpy/tests/reader_tests/gms/test_gms5_vissr_l1b.py	3	98.67%
satpy/tests/reader_tests/gms/test_gms5_vissr_navigation.py	3	97.18%

Totals
Change from base Build 12752022188:	0.01%
Covered Lines:	53664
Relevant Lines:	55774

---

💛 - Coveralls