workflows: disable s390x container builds for release

Signed-off-by: Patrick Stephens <pat@chronosphere.io>

.github/workflows/call-build-images.yaml

@@ -85,7 +85,6 @@ jobs:
           - amd64
           - arm64
           - arm/v7
-          - s390x
         target:
           - production
           - debug

.github/workflows/call-test-images.yaml

@@ -76,7 +76,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        arch: [ linux/amd64, linux/arm64, linux/arm/v7, linux/s390x ]
+        arch: [ linux/amd64, linux/arm64, linux/arm/v7 ]
         include:
           # Rather than extract the specific central arch we just provide it
           - arch: linux/amd64
@@ -85,8 +85,6 @@ jobs:
             expected: arm64
           - arch: linux/arm/v7
             expected: arm
-          - arch: linux/s390x
-            expected: s390x
     steps:
       - name: Log in to the Container registry
         uses: docker/login-action@v3