[TASK] Add support for PHP 8.1 functions

This change adds the symfony/polyfill-php81
package as dependency.

Used composer commands:

> composer req symfony/polyfill-php81
> composer req symfony/polyfill-php81 -d typo3/sysext/core --no-update

Resolves: #95666
Releases: master
Change-Id: Ib7553478167af36f1bf4c4da17fd225abf466c05
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71814
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>

composer.json

@@ -73,6 +73,7 @@
 		"symfony/polyfill-mbstring": "^1.16",
 		"symfony/polyfill-php73": "^1.16",
 		"symfony/polyfill-php80": "^1.16",
+		"symfony/polyfill-php81": "^1.23",
 		"symfony/property-access": "^4.4 || ^5.0",
 		"symfony/property-info": "^4.4 || ^5.0",
 		"symfony/routing": "^4.4 || ^5.0",

typo3/sysext/core/composer.json

@@ -60,6 +60,7 @@
 		"symfony/polyfill-mbstring": "^1.16",
 		"symfony/polyfill-php73": "^1.16",
 		"symfony/polyfill-php80": "^1.16",
+		"symfony/polyfill-php81": "^1.23",
 		"symfony/routing": "^4.4 || ^5.0",
 		"symfony/yaml": "^4.4 || ^5.0",
 		"typo3/class-alias-loader": "^1.0",