Update slim/psr7 requirement from ^1.3.0 to ^1.5

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@1.3.0...1.5)

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

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

Author: dependabot[bot]

composer.json

@@ -29,7 +29,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^9.5.10",
-        "slim/psr7": "^1.3.0",
+        "slim/psr7": "^1.5",
         "squizlabs/php_codesniffer": "^3.6"
     },
     "scripts": {