UPD tests: phpunit to latest version, also actions/checkout

Author: Thomas Kuschel

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
         runs-on: ${{ matrix.os }}
         steps:
             -   name: Checkout
-                uses: actions/checkout@v3
+                uses: actions/checkout@v4
             -   name: Setup PHP
                 uses: shivammathur/setup-php@v2
                 with:
@@ -24,4 +24,4 @@ jobs:
             fail-fast: false
             matrix:
                 os: [ubuntu-latest, windows-latest, macos-latest]
-                php-version: ['8.1', '8.2', '8.3']
+                php-version: ['8.1', '8.2', '8.3']

composer.json

@@ -26,7 +26,7 @@
         "phpseclib/phpseclib": "dev-master"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8.35|^5.7|^6.0|^9.4",
+        "phpunit/phpunit": "^10.5|^11.1",
         "squizlabs/php_codesniffer": "^3.0"
     },
     "suggest": {