ci: Drop support for ARM v7 platform (#2943)

This platform has had a deprecation notice for 6 months. It is not worth continuing to maintain support for.

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -22,7 +22,7 @@ body:
 
         We provide official support for
 
-        1. OS/ARCH: Linux on amd64/x86_64 or ARMv7 or ARM64
+        1. OS/ARCH: Linux on AMD64 (x86_64) and ARM64 (AArch64)
         2. Containerization platform: Docker and Docker Compose (i.e. based on Docker Engine)
 
         Other configurations are not officially supported, but there are maintainers that may be able to help you. This is the case for
@@ -111,9 +111,8 @@ body:
     attributes:
       label: What instruction set architecture is DMS running on?
       options:
-        - x86_64 / AMD64
+        - AMD64 / x86_64
-        - ARM64 / ARM v8 (and newer)
+        - ARM64 / AArch64 (ARM v8 and newer)
-        - ARM v7
         - Other (unsupported)
     validations:
       required: true

.github/workflows/generic_build.yml

@@ -76,13 +76,12 @@ jobs:
       - name: 'Set up QEMU'
         uses: docker/setup-qemu-action@v2.1.0
         with:
-          platforms: arm64,arm
+          platforms: arm64
 
       - name: 'Set up Docker Buildx'
         uses: docker/setup-buildx-action@v2.2.1
 
-      # NOTE: AMD64 can build within 2 minutes, ARM adds 13 minutes. 330MB each
+      # NOTE: AMD64 can build within 2 minutes
-      # ARMv7 can build in parallel, adding no extra time (but does add 150MB cache size).
       - name: 'Build images'
         uses: docker/build-push-action@v3.2.0
         with:

.github/workflows/generic_publish.yml

@@ -37,7 +37,7 @@ jobs:
       - name: 'Set up QEMU'
         uses: docker/setup-qemu-action@v2.1.0
         with:
-          platforms: arm64,arm
+          platforms: arm64
 
       - name: 'Set up Docker Buildx'
         uses: docker/setup-buildx-action@v2.2.1
@@ -78,7 +78,7 @@ jobs:
           build-args: |
             VCS_REVISION=${{ github.sha }}
             VCS_VERSION=${{ steps.get-version.outputs.version }}
-          platforms: linux/amd64,linux/arm/v7,linux/arm64
+          platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ steps.prep.outputs.tags }}
           cache-from: type=local,src=/tmp/.buildx-cache

.github/workflows/scheduled_builds.yml

@@ -13,7 +13,7 @@ jobs:
     name: 'Build Images'
     uses: docker-mailserver/docker-mailserver/.github/workflows/generic_build.yml@master
     with:
-      platforms: linux/amd64,linux/arm/v7,linux/arm64
+      platforms: linux/amd64,linux/arm64
 
   publish-images:
     name: 'Publish Images'

.github/workflows/test_merge_requests.yml

@@ -30,8 +30,8 @@ jobs:
     name: 'Build ARM64 Image'
     # Dependency ensures the cache-key is only created for AMD64 builds.
     # ARM64 will not be able to use this cache, building from scratch each time.
-    # Expect about 13 minutes build time until adopting `type=gha` with scopes for cache.
+    # Expect about 2 minutes extra build time until adopting `type=gha` with scopes for cache.
     needs: build-image-amd64
     uses: docker-mailserver/docker-mailserver/.github/workflows/generic_build.yml@master
     with:
-      platforms: linux/arm/v7,linux/arm64
+      platforms: linux/arm64