This reverts commit 4f7f706a63.
Version hygiene belongs to the pipeline that mints chart versions, not to the
chart. The build workflow now caps the version slug so litellm-<version> fits
the 63 byte label budget, which removes the overflow at the source rather than
silently truncating a value operators use to identify the build.
Drops the litellm.chart helper, restores the direct helm.sh/chart printf, and
removes tests/chart_label_tests.yaml. Both chart suites stay green:
helm unittest -f 'tests/*.yaml' helm/litellm # 20 passed
helm unittest -f 'tests/*.yaml' helm/litellm-helm # 69 passed