Issue #3421111: Upgrade Composer to ^2.7.0.

Closes #3421111

composer/Metapackage/DevDependencies/composer.json

@@ -10,7 +10,7 @@
         "behat/mink": "^1.11",
         "behat/mink-browserkit-driver": "^2.2",
         "colinodell/psr-testlogger": "^1.2",
-        "composer/composer": "^2.7",
+        "composer/composer": "^2.7.0",
         "drupal/coder": "^8.3.10",
         "justinrainbow/json-schema": "^5.2",
         "lullabot/mink-selenium2-driver": "^1.7",