[build] Overhaul Linux builds and refactor release workflow (#13997)

- Use `manylinux-shared` images for Linux builds
- Discontinue `yt-dlp_linux_armv7l`/`linux_armv7l_exe` release binary
- Add `yt-dlp_linux_armv7l.zip`/`linux_armv7l_dir` release binary
- Add `yt-dlp_musllinux` and `yt-dlp_musllinux_aarch64` release binaries
- Migrate `linux_exe` build strategy from staticx+musl to manylinux2014/glibc2.17
- Rewrite release.yml's "unholy bash monstrosity" as devscripts/setup_variables.py

Closes #10072, Closes #10630, Closes #10578, Closes #13976, Closes #13977, Closes #14106
Authored by: bashonly

devscripts/update_changelog.py

@@ -20,7 +20,9 @@ if __name__ == '__main__':
         '--changelog-path', type=Path, default=Path(__file__).parent.parent / 'Changelog.md',
         help='path to the Changelog file')
     args = parser.parse_args()
-    new_entry = create_changelog(args)
 
     header, sep, changelog = read_file(args.changelog_path).partition('\n### ')
-    write_file(args.changelog_path, f'{header}{sep}{read_version()}\n{new_entry}\n{sep}{changelog}')
+    current_version = read_version()
+    if current_version != changelog.splitlines()[0]:
+        new_entry = create_changelog(args)
+        write_file(args.changelog_path, f'{header}{sep}{current_version}\n{new_entry}\n{sep}{changelog}')