Modify source in Dockerfile for testing (#1475)

Author: Steboss

.github/container/Dockerfile.axlearn

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1-labs
 ARG BASE_IMAGE=ghcr.io/nvidia/jax-mealkit:jax
-ARG URLREF_AXLEARN=https://github.com/apple/axlearn.git#main
+ARG URLREF_AXLEARN=https://github.com/Steboss/axlearn.git#sbosisio/working_branch
 ARG SRC_PATH_AXLEARN=/opt/axlearn
 
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