Update fgrosse/phpasn1 requirement from ^2.0 to ^2.4

Updates the requirements on [fgrosse/phpasn1](https://github.com/FGrosse/PHPASN1) to permit the latest version.
- [Release notes](https://github.com/FGrosse/PHPASN1/releases)
- [Changelog](https://github.com/fgrosse/PHPASN1/blob/master/CHANGELOG.md)
- [Commits](fgrosse/PHPASN1@2.0.0...v2.4.0)

---
updated-dependencies:
- dependency-name: fgrosse/phpasn1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -58,7 +58,7 @@
         "ext-openssl": "*",
         "ext-sodium": "*",
         "brick/math": "^0.9|^0.10",
-        "fgrosse/phpasn1": "^2.0",
+        "fgrosse/phpasn1": "^2.4",
         "paragonie/constant_time_encoding": "^2.4",
         "psr/event-dispatcher": "^1.0",
         "psr/http-client": "^1.0",