Add php 8 to packages' build matrices; normalize composer reqs

Author: andrewmy

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.3', '7.4']
+        php: ['7.3', '7.4', '8.0']
 
     name: PHP ${{ matrix.php }} tests
 

composer.json

@@ -37,7 +37,7 @@
         "enqueue/async-command": "0.10.x-dev",
         "php-amqplib/php-amqplib": "^2.7",
         "doctrine/doctrine-bundle": "~1.2|^2",
-        "doctrine/mongodb-odm-bundle": "^3.5|^4",
+        "doctrine/mongodb-odm-bundle": "^3.5|^4.3",
         "alcaeus/mongo-php-adapter": "^1.0",
         "symfony/browser-kit": "^4.3|^5",
         "symfony/expression-language": "^4.3|^5",