This is according to our formal, published, policy to only support
EOL PHP after 6 months.
See https://phpspreadsheet.readthedocs.io/en/latest/#php-version-support
Also share the exact same dev deps across all PHP version for GitHub
Actions so runs are faster, much most importantly they are stable and
predictable. And we decide manually when we want to migrate to PHPUnit
10.
Fixes#3634Closes#3710
`master` is now the only permanent branch. Features and fixes should be merged
into `master` when stable. Pull requests should be forked from `master`.
`develop` branch disappear entirely in favor of temporary features/fixes branches.
Adrien Crivelli
MarkBaker