Update slim/psr7 requirement from ^1.6 to ^1.7

Updates the requirements on [slim/psr7](https://github.com/slimphp/Slim-Psr7) to permit the latest version.
- [Release notes](https://github.com/slimphp/Slim-Psr7/releases)
- [Commits](slimphp/Slim-Psr7@1.6...1.7.0)

---
updated-dependencies:
- dependency-name: slim/psr7
  dependency-type: direct:production
...

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

composer.json

@@ -20,7 +20,7 @@
         "php": "^8.2",
         "ext-json": "*",
         "php-di/php-di": "^7.0",
-        "slim/psr7": "^1.6",
+        "slim/psr7": "^1.7",
         "slim/slim": "^4.13",
         "slim/twig-view": "^3.4",
         "symfony/translation": "^7.0",