Update test suite to future-proof base images

.github/workflows/ci.yml

@@ -11,8 +11,8 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu-20.04
-          - windows-2019
+          - ubuntu-22.04
+          - windows-2022
         php:
           - 8.2
           - 8.1
@@ -53,13 +53,11 @@ jobs:
 
   PHPUnit-hhvm:
     name: PHPUnit (HHVM)
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
     continue-on-error: true
+    container: hhvm/hhvm:3.30-lts-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: azjezz/setup-hhvm@v1
-        with:
-          version: lts-3.30
-      - run: composer self-update --2.2 # downgrade Composer for HHVM
-      - run: hhvm $(which composer) install
+      - uses: actions/checkout@v1
+      - run: curl -O https://getcomposer.org/download/latest-2.2.x/composer.phar
+      - run: hhvm composer.phar install
       - run: hhvm vendor/bin/phpunit