[DOCS] Add trailing backtick to php-role

Releases: main
Resolves: #104864
Change-Id: I0c5ee461bb9ea124c9e2931386e1b301b8d1f5f3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/85930


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>