With PhpUnit 10 came the ability to use Php attributes rather than doc-block annotations for things like "data provider". PhpUnit 11 deprecates the use of annotations, and PhpUnit 12 will not not permit their use. Since PhpUnit 11 requires Php8.2+, we cannot adopt it as long as we support Php8.1, which will continue to be the case for some time. However, there is no penalty for early adoption.
Php-cs-fixer can use:
```
'php_unit_attributes' => ['keep_annotations' => false],
```
This allows us to run `composer fix` to automate all the needed changes. No manual changes were needed for any of the test members.
With this change, PhpUnit 9 can no longer be used with the test suite. File composer.json is updated to reflect that reality, and phpunit9.xml.dist, which has been supplied in case anyone needed to use PhpUnit 9, is no longer required, and is thus deleted. For now, PhpUnit 11 is not being added as a possibility.
No source code is changed in this PR.
Implement SPILL for dynamic arrays. Calculating a dynamic array function will result in a SPILL error if it attempts to overlay a non-null cell which was not part of its previous calculation. Furthermore, it will set to null all cells which were part of its previous calculation but which are not part of the current one (i.e. one or both of the dimensions of the calculation is smaller than it had been); this should also apply for spills (whose result is reduced to 1*1).
Excel will stop you from changing the value in any cell in a dynamic array except the formula cell itself. I have not built this particular aspect into PhpSpreadsheet.
As usual, MS has taken some unusual steps here. If the result of a dynamic array calculation is #SPILL!, it will nevertheless be written to the xml as #VALUE!. It recognizes this situation by adding a new `vm` attribute to the cell, and expanding metadata.xml to recognize this.
A new optional parameter `$reduceArrays` is added to `toArray` and related functions. This will reduce a dynamic array to its first cell, which seems more useful than outputing it as an array (default).
oleibman