Revert "Use docker/login-action"

This reverts commit 7ac896a.

.github/actions/push_image/action.yml

@@ -21,17 +21,13 @@ inputs:
 runs:
   using: composite
   steps:
-  - name: Login to Docker Hub
-    uses: docker/login-action@v3
-    with:
-      username: ${{ secrets.DOCKER_USER }}
-      password: ${{ secrets.DOCKER_PASS }}
   - name: Push docker image to rubylang
     run: |-
+      echo $DOCKER_PASS | docker login -u $DOCKER_USER --password-stdin
       rake docker:push ruby_version=${{ inputs.ruby_version }} \
                        ubuntu_version=${{ inputs.ubuntu_version }} \
                        image_version_suffix=${{ inputs.image_version_suffix }} \
                        ${{ inputs.nightly }}nightly=yes${{ inputs.nightly }} \
                        tag_suffix=${{ inputs.tag_suffix }} \
                        latest_tag=${{ inputs.latest_tag }}
-    shell: bash
+    shell: bash