Update pipeline.yml to simplify BUILD_DATE assignment by removing unnecessary fromJSON conversion

Author: mattmattox

.github/workflows/pipeline.yml

@@ -76,7 +76,7 @@ jobs:
           build-args: |
             VERSION=v${{ github.run_number }}
             GIT_COMMIT=${{ github.sha }}
-            BUILD_DATE=${{ fromJSON('["' + github.event.repository.updated_at + '"]')[0] }}
+            BUILD_DATE=${{ github.event.repository.updated_at }}
 
       # Move cache for next build
       - name: Move cache