Use composer v1 in CI

Not all dev dependencies are v2 ready.

maglnet/composer-require-checker has a dependency to
ocramius/package-versions version which requires v1 composer API.
Once a newer version is required, we can use v2.

.github/workflows/ci.yaml

@@ -46,6 +46,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest --no-plugins
 
@@ -73,6 +76,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -108,6 +114,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -144,6 +153,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -183,6 +195,9 @@ jobs:
       - name: Start MySQL
         run: sudo /etc/init.d/mysql start
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -213,6 +228,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest
 
@@ -237,6 +255,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer V1 until all dev dependencies are ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest