composer(deps): update php-di/php-di requirement from ^6.0 to ^6.4

Updates the requirements on [php-di/php-di](https://github.com/PHP-DI/PHP-DI) to permit the latest version.
- [Release notes](https://github.com/PHP-DI/PHP-DI/releases)
- [Commits](PHP-DI/PHP-DI@6.0.0...6.4.0)

---
updated-dependencies:
- dependency-name: php-di/php-di
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -18,7 +18,7 @@
         "php": "^7.4 || ^8.0",
         "medicalmundi/npi-registry-php-sdk": "^0.1",
         "openemr/oe-module-installer-plugin": "^0.1.",
-        "php-di/php-di": "^6.0",
+        "php-di/php-di": "^6.4",
         "symfony/event-dispatcher": "^5.4",
         "symfony/http-foundation": "^4.4 || ^5.4",
         "twig/twig": "^2.12 || ^3.5"