Bump codecov/codecov-action from 5 to 6

Update RTD to ubuntu 24 and miniforge

Fix version number in changelog

Update changelog for v0.12.1

Merge pull request #223 from pnuu/bugfix-downloader-skip-empty-lines

[pre-commit.ci] pre-commit autoupdate

Add missing variable

Simplify code for empty platform string

Add one more empty line

Handle empty trailing lines in TLEs

Parametrize test_read_tle_files and test different combinations

Make Downloader tests pytest compatible

Update release notes for 1.12.0

Merge pull request #222 from djhoese/relicense-apache2

Relicense to Apache 2.0