add option to set build-kit base tag

Signed-off-by: Andreas Heinrich <[email protected]>

.github/workflows/continuous_integration.yml

@@ -80,6 +80,11 @@ on:
         required: false
         default: '.ci/build-kit/scripts'
         type: string
+      build_kit_base_image_tag:
+        description: 'The tag of the base image to use for the build kit'
+        required: false
+        default: ''
+        type: string
       # Build inputs
       ctest_report_path:
         description: 'The path to the ctest report, relative to the github workspace'
@@ -249,6 +254,12 @@ jobs:
             exit 1
           fi
 
+          # if inputs.build_kit_base_image_tag is != "", use it as the tag
+          if [ -n "${{ inputs.build_kit_base_image_tag }}" ]; then
+            echo "Using inputs.build_kit_base_image_tag as tag"
+            TAG="${{ inputs.build_kit_base_image_tag }}"
+          fi
+
           echo "latest_tag=$TAG" >> $GITHUB_OUTPUT
 
   build-the-build-kit: