GH Actions: version update for ramsey/composer-install

The action used to install Composer packages and handle the caching has released a new major (and some follow-up patch releases), which means, the action reference needs to be updated to benefit from it.

Refs:
* https://github.com/ramsey/composer-install/releases/tag/2.0.0
* https://github.com/ramsey/composer-install/releases/tag/2.0.1
* https://github.com/ramsey/composer-install/releases/tag/2.0.2

Author: jrfnl

.github/workflows/cs.yml

@@ -31,7 +31,7 @@ jobs:
       # Install dependencies and handle caching in one go.
       # @link https://github.com/marketplace/actions/install-composer-dependencies
       - name: Install Composer dependencies
-        uses: "ramsey/composer-install@v1"
+        uses: "ramsey/composer-install@v2"
 
       - name: Check PHP code style
         continue-on-error: true

.github/workflows/test.yml

@@ -44,12 +44,12 @@ jobs:
       # @link https://github.com/marketplace/actions/install-composer-dependencies
       - name: Install Composer dependencies - normal
         if: ${{ matrix.experimental == false }}
-        uses: "ramsey/composer-install@v1"
+        uses: "ramsey/composer-install@v2"
 
       # For the PHP "nightly", we need to install with ignore platform reqs as not all dependencies allow it.
       - name: Install Composer dependencies - with ignore platform
         if: ${{ matrix.experimental == true }}
-        uses: "ramsey/composer-install@v1"
+        uses: "ramsey/composer-install@v2"
         with:
           composer-options: --ignore-platform-reqs