github actions: Add skip_kabi workflow input for CLK kernel builds

CLK kernels don't require a kABI compatibility check. This change
leverages the skipkabi support already built into the container's
kernel_build.sh.

The -u flag on build_kernel.sh overrides which underlying script the
container runs, replacing the default with:
  /usr/local/bin/kernel_build.sh skipkabi

A bash array is used for BUILD_ARGS so the podman invocation stays
clean and the default (no skip_kabi) produces no behavioral change.

Author: bmastbergen

.github/workflows/kernel-build-and-test-multiarch.yml

@@ -8,6 +8,11 @@ on:
         required: false
         type: string
         default: 'x86_64,aarch64'
+      skip_kabi:
+        description: 'Skip kABI compatibility check'
+        required: false
+        type: boolean
+        default: false
     secrets:
       APP_ID:
         required: true
@@ -103,6 +108,11 @@ jobs:
         df -h
         cat /proc/cpuinfo
         chmod +x kernel-container-build/build-container/*.sh
+        BUILD_ARGS=()
+        if [ "${{ inputs.skip_kabi }}" = "true" ]; then
+          # -u overrides the build container's default command (kernel_build.sh)
+          BUILD_ARGS=(-u "/usr/local/bin/kernel_build.sh skipkabi")
+        fi
         podman run --rm --pull=always \
           --privileged \
           --device=/dev/fuse \
@@ -114,7 +124,7 @@ jobs:
           -v "$PWD/kernel-container-build/container/check_kabi.sh":/usr/libexec/check_kabi.sh:ro \
           --security-opt label=disable \
           pulp.prod.ciq.dev/ciq/cicd/lts-images/builder \
-          /usr/local/build-scripts/build_kernel.sh 2>&1 | tee output/kernel-build.log
+          /usr/local/build-scripts/build_kernel.sh "${BUILD_ARGS[@]}" 2>&1 | tee output/kernel-build.log
         sudo dmesg
 
     # Upload kernel compilation logs