When merging configs, do not merge data sources (#79)

* When merging configs, do not merge data sources

* Add todo

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Co-authored-by: Srini Iyer <sviyer@meta.com>

bytelatent/config_parser.py

@@ -58,6 +58,11 @@ def parse_args_with_default(
     if default_cfg is not None:
         ordered_cfgs.insert(0, default_cfg)
     cfg = OmegaConf.merge(*ordered_cfgs)
+    # TODO: Change sources to list[tuple,str, float]] so that this special case isn't needed
+    for c in reversed(ordered_cfgs):
+        if "data" in c and "sources" in c["data"]:
+            cfg["data"]["sources"] = c["data"]["sources"]
+            break
     return OmegaConf.to_container(cfg, resolve=True, throw_on_missing=True)