ci(SDK-4666): Add support for forthcoming PHP 8.3 release (#733)

### Changes

This pull request adds the forthcoming PHP 8.3 runtime to the continuous
integration test matrix.

### References

N/A

### Testing

This pull request expands the existing continuous integration testing.

### Contributor Checklist

- [x] I agree to adhere to the [Auth0 General Contribution
Guidelines](https://github.com/auth0/open-source-template/blob/master/GENERAL-CONTRIBUTING.md).
- [x] I agree to uphold the [Auth0 Code of
Conduct](https://github.com/auth0/open-source-template/blob/master/CODE-OF-CONDUCT.md).

.github/workflows/matrix.json

@@ -1,6 +1,7 @@
 {
   "include": [
     { "php": "8.1" },
-    { "php": "8.2" }
+    { "php": "8.2" },
+    { "php": "8.3" }
   ]
 }

composer.json

@@ -107,7 +107,10 @@
     "pest:fast": [
       "@pest --parallel"
     ],
-    "phpcs": "@php vendor/bin/php-cs-fixer fix --dry-run --diff",
+    "phpcs": [
+      "@putenv PHP_CS_FIXER_IGNORE_ENV=1",
+      "@php vendor/bin/php-cs-fixer fix --dry-run --diff"
+    ],
     "phpcs:fix": "@php vendor/bin/php-cs-fixer fix",
     "phpstan": "@php vendor/bin/phpstan analyze",
     "psalm": "@php vendor/bin/psalm",