Fix load-workflow-variables issue where config file cannot be found

.github/actions/load-workflow-variables/action.yml

@@ -33,20 +33,30 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: 'Sanitize Input Filepath'
+      id: 'sanitize_filepath'
+      shell: 'bash'
+      env:
+        CONFIG_REL_PATH: '${{ inputs.filepath }}'
+      run: |-
+        relpath=${CONFIG_REL_PATH}
+        filepath=$(echo "$relpath" | sed 's/^\.\///')
+        echo "CONFIG_PATH=$filepath" >> "$GITHUB_OUTPUT"
+
     - name: 'Get Approved Configuration File'
       uses: 'actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11' # ratchet:actions/checkout@v4
       with:
         ref: '${{ github.event.repository.default_branch }}'
         path: 'load-workflow-variables/${{ github.sha }}'
         sparse-checkout: |
-          ${{ inputs.filepath }}
+          ${{ steps.sanitize_filepath.outputs.CONFIG_PATH }}
         sparse-checkout-cone-mode: 'false'
 
     - name: 'Load Workflow Variables'
       shell: 'bash'
       env:
         WORKING_DIRECTORY: '${{ inputs.working_directory }}'
-        FILEPATH: 'load-workflow-variables/${{ github.sha }}/${{ inputs.filepath }}'
+        FILEPATH: 'load-workflow-variables/${{ github.sha }}/${{ steps.sanitize_filepath.outputs.CONFIG_PATH }}'
         FAIL_ON_MISSING: '${{ inputs.fail_on_missing }}'
       run: |-
         FILEPATH=$(realpath "${FILEPATH}")