chore(deps): Update psr/http-message requirement || ^2.0

Updates the requirements on [psr/http-message](https://github.com/php-fig/http-message) to permit the latest version.
- [Release notes](https://github.com/php-fig/http-message/releases)
- [Changelog](https://github.com/php-fig/http-message/blob/master/CHANGELOG.md)
- [Commits](php-fig/http-message@1.1...2.0)

---
updated-dependencies:
- dependency-name: psr/http-message
  dependency-type: direct:production
...

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

composer.json

@@ -21,7 +21,7 @@
         "psr/http-client-implementation": "^1",
         "psr/http-factory": "^1.0.1",
         "psr/http-factory-implementation": "^1",
-        "psr/http-message": "^1.1",
+        "psr/http-message": "^1.1 || ^2.0",
         "psr/http-message-implementation": "^1",
         "psr/http-server-handler": "^1.0",
         "psr/http-server-middleware": "^1.0"