Add ubuntu arm64 pwsh runner helper image

Author: saracen

dockerfiles/runner-helper/docker-bake.hcl

@@ -95,12 +95,18 @@ target "ubuntu" {
 target "ubuntu-pwsh" {
   inherits = ["base"]
 
-  platforms = ["linux/amd64"]
+  name = "ubuntu-${replace(platform, "/", "-")}-pwsh"
+
+  matrix = {
+    platform = ["linux/amd64", "linux/arm64"]
+  }
+
+  platforms = [platform]
   args = {
     BASE_IMAGE = "${RUNNER_IMAGES_REGISTRY}/runner-helper:${RUNNER_IMAGES_VERSION}-ubuntu-pwsh"
   }
 
-  output = ["type=oci,dest=./../../out/helper-images/ubuntu-x86_64-pwsh.tar,tar=true"]
+  output = ["type=oci,dest=./../../out/helper-images/ubuntu-${split("/", platform)[1] == "amd64" ? "x86_64" : split("/", platform)[1]}-pwsh.tar,tar=true"]
 }
 
 target "ubi-fips" {

scripts/pusher/helper-images.json

@@ -128,6 +128,9 @@
         "ubuntu-x86_64-pwsh": [
             "ubuntu-x86_64-%-pwsh"
         ],
+        "ubuntu-arm64-pwsh": [
+            "ubuntu-arm64-%-pwsh"
+        ],
         "ubuntu-x86_64": [
             "ubuntu-x86_64-%"
         ],