Validate composer.json as part of CI workflows (#1636)

* Add workflow to validate composer.json

* Add missing description to composer.json

* Add missing newline at EOF

* Auto-detect PHP version to use

.github/workflows/composer-validate.yml

@@ -0,0 +1,30 @@
+name: "Check validity of composer.json"
+
+on:
+  pull_request:
+    branches:
+      - "v*.*"
+      - "master"
+      - "feature/*"
+  push:
+    branches:
+      - "v*.*"
+      - "master"
+      - "feature/*"
+
+jobs:
+  composer-validate:
+    name: "Check validity of composer.json"
+    runs-on: "ubuntu-24.04"
+
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v4"
+        with:
+          submodules: true
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+
+      - name: "Run composer validate"
+        run: "composer validate --strict"

composer.json

@@ -1,5 +1,6 @@
 {
   "name": "mongodb/mongodb-extension",
+  "description": "MongoDB driver extension",
   "type": "php-ext",
   "keywords": ["database", "driver", "mongodb", "persistence"],
   "homepage": "https://jira.mongodb.org/browse/PHPC",
@@ -69,4 +70,4 @@
       }
     ]
   }
-}
+}