fix(ci): make kernel pin work from CLI (#2495)

If you specified --kernel-pin from cli it will now correctly verify and
donwload the right version (instead of the newest one), if it's
specified in the Justfile and CLI then CLI wins.

The pin that is always set to an empty string would override it.

Author: renner0e

Justfile

@@ -148,31 +148,32 @@ build $image="aurora" $tag="latest" $flavor="main" $rechunk="false" $ghcr="false
     # skopeo list-tags docker://ghcr.io/ublue-os/akmods | jq -r '.Tags | map(select(contains("coreos-stable-44")))'
 
     ARCH=$(arch)
-
-    case "${tag}" in
-            stable)
-                if [[ "${ARCH}" == "x86_64" ]]; then
-                    # <Here is a link why we have it pinned>
-                    kernel_pin=""
-                elif [[ "${ARCH}" == "aarch64" ]]; then
-                    kernel_pin=""
-                fi
-                ;;
-            latest)
-                if [[ "${ARCH}" == "x86_64" ]]; then
-                    kernel_pin=""
-                elif [[ "${ARCH}" == "aarch64" ]]; then
-                    kernel_pin=""
-                fi
-                ;;
-            testing)
-                if [[ "${ARCH}" == "x86_64" ]]; then
-                    kernel_pin=""
-                elif [[ "${ARCH}" == "aarch64" ]]; then
-                    kernel_pin=""
-                fi
-                ;;
-    esac
+    if [[ -z "${kernel_pin:-}" ]]; then
+      case "${tag}" in
+              stable)
+                  if [[ "${ARCH}" == "x86_64" ]]; then
+                      # <Here is a link why we have it pinned>
+                      kernel_pin=""
+                  elif [[ "${ARCH}" == "aarch64" ]]; then
+                      kernel_pin=""
+                  fi
+                  ;;
+              latest)
+                  if [[ "${ARCH}" == "x86_64" ]]; then
+                      kernel_pin=""
+                  elif [[ "${ARCH}" == "aarch64" ]]; then
+                      kernel_pin=""
+                  fi
+                  ;;
+              testing)
+                  if [[ "${ARCH}" == "x86_64" ]]; then
+                      kernel_pin=""
+                  elif [[ "${ARCH}" == "aarch64" ]]; then
+                      kernel_pin=""
+                  fi
+                  ;;
+      esac
+    fi
 
     if [[ -z "${kernel_pin:-}" ]]; then
         kernel_release=$(skopeo inspect --retry-times 3 docker://ghcr.io/ublue-os/akmods:"${akmods_flavor}"-"${fedora_version}" | jq -r '.Labels["ostree.linux"]')