Drop support for arm/v7 on Alpine

Some strange issue make so that this arch fails to build on Alpine.
To not hinder the 3.0.0 release we drop this arch, and hopefully
we can reintroduce it in the future.

More info here: pyca/cryptography#6673
and here: rust-lang/cargo#2808

.github/workflows/build_latest.yml

@@ -78,6 +78,5 @@ jobs:
           platforms: |
             linux/amd64
             linux/arm64
-            linux/arm/v7
           push: ${{ github.event_name != 'pull_request' }}
           tags: jonasal/nginx-certbot:latest-alpine

.github/workflows/build_tags.yml

@@ -82,7 +82,6 @@ jobs:
           platforms: |
             linux/amd64
             linux/arm64
-            linux/arm/v7
           pull: true
           no-cache: true
           push: true

src/Makefile

@@ -21,7 +21,7 @@ dev:
 	docker buildx build --build-arg BUILDX_QEMU_ENV=true --platform linux/amd64,linux/386,linux/arm64,linux/arm/v7 --tag jonasal/nginx-certbot:dev -f ./Dockerfile ./
 
 dev-alpine:
-	docker buildx build --platform linux/amd64,linux/386,linux/arm64,linux/arm/v7 --tag jonasal/nginx-certbot:dev-alpine -f ./Dockerfile-alpine ./
+	docker buildx build --platform linux/amd64,linux/arm64 --tag jonasal/nginx-certbot:dev-alpine -f ./Dockerfile-alpine ./
 
 push:
 	docker buildx build --build-arg BUILDX_QEMU_ENV=true --platform linux/amd64,linux/386,linux/arm64,linux/arm/v7 --tag jonasal/nginx-certbot:dev --pull --no-cache --push .