feat: add ARM64 (linux/arm64) support for multi-arch Docker builds

Add QEMU emulation and multi-platform support to both CI workflows:
- test.yml: add platform matrix dimension (amd64 + arm64) for full cross-arch testing
- publish.yml: build and push multi-arch manifests (linux/amd64,linux/arm64)

Author: naorpeled

.github/workflows/publish.yml

@@ -46,6 +46,9 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v4
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
 
@@ -64,6 +67,7 @@ jobs:
         with:
           context: .
           push: true
+          platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |

.github/workflows/test.yml

@@ -12,23 +12,19 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        include:
-          - pg_version: "17.9"
-            postgis_version: "3.6.2"
-            pgvector_version: "0.8.2"
-          - pg_version: "16.13"
-            postgis_version: "3.6.2"
-            pgvector_version: "0.8.2"
-          - pg_version: "15.17"
-            postgis_version: "3.6.2"
-            pgvector_version: "0.8.2"
-          - pg_version: "14.22"
-            postgis_version: "3.6.2"
-            pgvector_version: "0.8.2"
+        platform:
+          - linux/amd64
+          - linux/arm64
+        pg_version: ["17.9", "16.13", "15.17", "14.22"]
+        postgis_version: ["3.6.2"]
+        pgvector_version: ["0.8.2"]
 
     steps:
       - uses: actions/checkout@v6
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v4
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
 
@@ -37,6 +33,7 @@ jobs:
         with:
           context: .
           load: true
+          platforms: ${{ matrix.platform }}
           tags: postgres-test:pg${{ matrix.pg_version }}
           build-args: |
             PG_VERSION=${{ matrix.pg_version }}
@@ -46,9 +43,10 @@ jobs:
       - name: Start PostgreSQL container and test extensions
         run: |
           IMAGE_TAG="postgres-test:pg${{ matrix.pg_version }}"
-          echo "Testing image: $IMAGE_TAG"
+          echo "Testing image: $IMAGE_TAG (platform: ${{ matrix.platform }})"
 
           docker run -d --name test-db \
+            --platform ${{ matrix.platform }} \
             -e POSTGRES_PASSWORD=test \
             -e POSTGRES_USER=test \
             -e POSTGRES_DB=test \