feat: build Python and Django images for aarch64

Add configuration to build Python and Django base images for aarch64.

We skip some images which timeout when building under aarch64 because
grpcio takes _forever_ to build.

Closes #73

.gitlab-ci.yml

@@ -77,6 +77,8 @@ python-3.11-alpine:
 python-3.8-alpine3.10:
   extends: .build_and_push
   variables:
+    # In alpine 3.10, rust is not available for arm64 and so we only build an amd64 variant of this
+    # image.
     IMAGE_TYPE: python-alpine
     IMAGE_NAME: python
     TAGS: 3.8-alpine3.10
@@ -93,6 +95,7 @@ python-3.8-slim:
     TAGS: 3.8-slim
     PYTHON_VERSION: "3.8"
     ENVSUBST_DOCKERFILE: "True"
+    IMAGE_ARCHS: "linux/amd64,linux/arm64"
 
 python-3.9-slim:
   extends: .build_and_push
@@ -102,6 +105,7 @@ python-3.9-slim:
     TAGS: 3.9-slim slim
     PYTHON_VERSION: "3.9"
     ENVSUBST_DOCKERFILE: "True"
+    IMAGE_ARCHS: "linux/amd64,linux/arm64"
 
 python-3.10-slim:
   extends: .build_and_push
@@ -111,6 +115,7 @@ python-3.10-slim:
     TAGS: 3.10-slim slim
     PYTHON_VERSION: "3.10"
     ENVSUBST_DOCKERFILE: "True"
+    IMAGE_ARCHS: "linux/amd64,linux/arm64"
 
 python-3.11-slim:
   extends: .build_and_push
@@ -120,6 +125,7 @@ python-3.11-slim:
     TAGS: 3.11-slim slim latest
     PYTHON_VERSION: "3.11"
     ENVSUBST_DOCKERFILE: "True"
+    IMAGE_ARCHS: "linux/amd64,linux/arm64"
 
 django-3.2-python-3.9-alpine:
   extends: .build_and_push