Bump stripe/stripe-php in /_backend in the composer-patching group

Bumps the composer-patching group in /_backend with 1 update: [stripe/stripe-php](https://github.com/stripe/stripe-php).


Updates `stripe/stripe-php` from 21.1.1 to 21.2.0
- [Release notes](https://github.com/stripe/stripe-php/releases)
- [Changelog](https://github.com/stripe/stripe-php/blob/master/CHANGELOG.md)
- [Commits](stripe/stripe-php@v21.1.1...v21.2.0)

---
updated-dependencies:
- dependency-name: stripe/stripe-php
  dependency-version: 21.2.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: composer-patching
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

_backend/composer.json

@@ -14,7 +14,7 @@
         }
     },
     "require": {
-        "stripe/stripe-php": "21.1.1",
+        "stripe/stripe-php": "21.2.0",
         "erusev/parsedown-extra": "^0.9",
         "geoip2/geoip2": "^3.0",
         "ext-intl": ">=7",