fix(ci): omit null layer metadata fields

Placeholder layer versions can omit optional metadata such as LicenseInfo. Remove null values from the publish request so the AWS CLI accepts these versions during partition deployment.

Refs #7975

Author: dreamorosi

.github/workflows/layers_partitions.yml

@@ -159,7 +159,7 @@ jobs:
       - name: Create Layer
         id: create-layer
         run: |
-          cat '${{ matrix.layer }}-${{ matrix.arch }}.json' | jq '{"LayerName": "${{ matrix.layer }}-${{ matrix.arch }}", "Description": .Description, "CompatibleRuntimes": .CompatibleRuntimes, "CompatibleArchitectures": .CompatibleArchitectures, "LicenseInfo": .LicenseInfo}' > input.json
+          jq '{"LayerName": "${{ matrix.layer }}-${{ matrix.arch }}", "Description": .Description, "CompatibleRuntimes": .CompatibleRuntimes, "CompatibleArchitectures": .CompatibleArchitectures, "LicenseInfo": .LicenseInfo} | with_entries(select(.value != null))' '${{ matrix.layer }}-${{ matrix.arch }}.json' > input.json
 
           LAYER_VERSION=$(aws --region ${{ matrix.region}} lambda publish-layer-version \
             --zip-file 'fileb://./${{ matrix.layer }}-${{ matrix.arch }}.zip' \