ci: automate build of Docker image for running CI

#3

.github/workflows/build-ci-runner-image.yml

@@ -0,0 +1,62 @@
+name: Docker image for CI
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - '.github/workflows/build-ci-runner-image.yml'
+      - 'docker/ci-runner.Dockerfile'
+  workflow_dispatch:
+    inputs:
+      nodejs_version:
+        description: 'Node.js version to use'
+        type: string
+        required: true
+      debian_version:
+        description: 'Debian codename version to use'
+        type: string
+        required: true
+
+env:
+  NODEJS_VERSION: ${{ inputs.nodejs_version || '22' }}
+  DEBIAN_VERSION: ${{ inputs.debian_version || 'trixie' }}
+
+  IMAGE_NAME: ghcr.io/${{ github.repository }}/ci-runner
+  DOCKERFILE_PATH: docker/ci-runner.Dockerfile
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+
+    steps:
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Prepare metadata for tags and labels
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.IMAGE_NAME }}
+          tags: |
+            type=raw,value=node-${{ env.NODEJS_VERSION }}-${{ env.DEBIAN_VERSION }}-slim
+          labels: |
+            org.opencontainers.image.title: Obsidian plugins CI runner
+            org.opencontainers.image.description=Docker image for building and testing obsidian plugins (with E2E tests support)
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          file: ${{ env.DOCKERFILE_PATH }}
+          build-args: |
+            NODEJS_VERSION=${{ env.NODEJS_VERSION }}
+            DEBIAN_VERSION=${{ env.DEBIAN_VERSION }}
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}