.github/workflows/compilers.yml: Specify a container running user as root.

Explicitly specify the root as a user to run tests in the containers.

Coming new ruby/ruby-ci-image images are required to run the container as
a regular user by default, while the root user is required to run the
compilers.yml. Add `id` command to print the user info.

Co-authored-by: fedor <fedor@cirruslabs.org>

.github/workflows/compilers.yml

@@ -168,8 +168,12 @@ jobs:
 
     name: ${{ matrix.entry.name }}
     runs-on: ubuntu-latest
-    container: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || 'clang-14' }}
+    container:
+      image: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || 'clang-14' }}
+      options: --user root
     steps:
+      - run: id
+        working-directory:
       - run: mkdir build
         working-directory:
       - name: setenv