Libs(Go): pluralize GO_MODULES in superlinter (#1353)

Follow-on from #1351 which I
didn't catch because editing the linter doesn't run the lints for the
different langs, so problems only surfaced when I rebased the other
branch... 😢

Author: svix-onelson

.github/workflows/other-lint.yml

@@ -40,7 +40,7 @@ jobs:
           VALIDATE_PYTHON_MYPY: false
           VALIDATE_PYTHON_PYLINT: false
           VALIDATE_GO: false
-          VALIDATE_GO_MODULE: false
+          VALIDATE_GO_MODULES: false
           VALIDATE_JSCPD: false
           VALIDATE_PHP_PHPSTAN: false
           VALIDATE_PHP_PSALM: false