Revert "[image-builder-bob] bump up buildkit (#20690)"

This reverts commit fd36244.

Author: geropl

.github/workflows/build.yml

@@ -4,7 +4,6 @@ permissions:
   contents: write # This is required for actions/checkout and create release
   pull-requests: write
   actions: write  # This is required for trigger another action which is used by JetBrains integrateion tests
-  packages: read
 on:
   pull_request:
     types: [ opened, edited ]
@@ -230,12 +229,6 @@ jobs:
           cat report.html >> $GITHUB_STEP_SUMMARY
 
           exit $RESULT
-      - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Leeway Build
         id: leeway
         shell: bash

components/image-builder-bob/leeway.Dockerfile

@@ -2,7 +2,7 @@
 # Licensed under the GNU Affero General Public License (AGPL).
 # See License.AGPL.txt in the project root for license information.
 
-FROM ghcr.io/gitpod-io/buildkit:v0.20.1-gitpod.2
+FROM eu.gcr.io/gitpod-core-dev/build/buildkit:v0.12.5-gitpod.0
 
 USER root
 RUN apk --no-cache add sudo bash \