Update simplesamlphp/assert requirement

Updates the requirements on [simplesamlphp/assert](https://github.com/simplesamlphp/assert) to permit the latest version.

Updates `simplesamlphp/assert` to 2.0.2
- [Release notes](https://github.com/simplesamlphp/assert/releases)
- [Commits](simplesamlphp/assert@v1.9.0...v2.0.2)

---
updated-dependencies:
- dependency-name: simplesamlphp/assert
  dependency-version: 2.0.2
  dependency-type: direct:production
  dependency-group: production-dependencies
...

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

Author: dependabot[bot]

composer.json

@@ -22,7 +22,7 @@
         "ext-openssl": "*",
         "ext-pdo": "*",
 
-        "simplesamlphp/assert": "~1.9",
+        "simplesamlphp/assert": "~2.0",
         "simplesamlphp/simplesamlphp": "~2.5@RC",
         "spomky-labs/cbor-php": "~3.2",
         "spomky-labs/pki-framework": "~1.4",