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.
Fix#3875. Even better, fix#2146, which has been open for 2.5 years.
Empty arguments are improperly placed on the stack; in particular, they are added without `onlyIf` and `onlyIfNot` attributes.This results in problems described in 3875.
IF has a somewhat unexpected design. In Excel, `IF(false, valueIfTrue)` evaluates as `false`, but `IF(false, valueIfTrue,)` evaluates as 0. This means that IF empty arguments should be handled in the same manner as MIN/MAX/MINA/MAXA, but you need to be careful to distinguish empty from omitted.
Also note that IF requires 2 operands - `IF(true)` is an error, but `IF(true,)` evaluates to 0.
Fix#3866. Excel normally treats a missing argument (e.g. `PRODUCT(2,3,)`) as null and ignores it. Not so for MIN/MAX/MINA/MAXA; for those, an empty argument is treated as zero. PhpSpreadsheet is changed to do the same.
oleibman