devops: forgot the z15 suffix

Signed-off-by: Aaron Teo <[email protected]>

Author: taronaeo

.github/workflows/release.yml

@@ -134,7 +134,7 @@ jobs:
         include:
           - build: 'x64'
             os: ubuntu-22.04
-          - build: 's390x' # z15 because our CI runners are on z15
+          - build: 's390x-z15' # z15 because our CI runners are on z15
             os: ubuntu-22.04-s390x
           # GGML_BACKEND_DL and GGML_CPU_ALL_VARIANTS are not currently supported on arm
           # - build: 'arm64'
@@ -164,7 +164,7 @@ jobs:
       - name: Build
         id: cmake_build
         run: |
-          if [ "${{ matrix.build }}" = "s390x" ]; then
+          if [ "${{ matrix.build }}" = "s390x-z15" ]; then
             cmake -B build \
               -DCMAKE_INSTALL_RPATH='$ORIGIN' \
               -DCMAKE_BUILD_WITH_INSTALL_RPATH=ON \