FEATURE: Update PHP Version in Behat Test docker file

Review instructions I updated the PHP Version for the behat Docker Container to keep everything up-to-date Checklist

[x] Code follows the PSR-2 coding style
[x] Tests have been created, run and adjusted as needed
[x] The PR is created against the lowest maintained branch
[ ] Reviewer - PR Title is brief but complete and starts with FEATURE|TASK|BUGFIX
[ ] Reviewer - The first section explains the change briefly for change-logs
[ ] Reviewer - Breaking Changes are marked with !!! and have upgrade-instructions

neos / neos-development-collection