kubernetes: suppress tqdm progress bars in all container pods

Inject TQDM_DISABLE=1 and HF_DATASETS_DISABLE_PROGRESS_BARS=1 into every
Kubernetes container's environment unless the component has already set
those keys explicitly (user values take precedence).

High-volume tqdm block-glyph output (█▉▊▋▌▍▎▏, 3-byte UTF-8) from
concurrent HF datasets workers (num_proc>1) is the dominant source of
non-ASCII bytes in pod log streams. Eliminating the glyphs at the source
makes the log stream pure ASCII for tokenization/packing phases, removing
any possibility of torn multi-byte sequences reaching the Kubernetes API
read path regardless of the defensive decode added in the previous commit.

Side effect: log sizes for heavy tokenization jobs drop significantly
(observed ~6 MB → tens of KB), since tqdm progress bars account for the
bulk of the raw byte volume.

Author: morgan-wowk

cloud_pipelines_backend/launchers/kubernetes_launchers.py

@@ -69,6 +69,16 @@
 # Environment variables for multi-node execution.
 _MULTI_NODE_NODE_INDEX_ENV_VAR_NAME = "_TANGLE_MULTI_NODE_NODE_INDEX"
 
+# Environment variables injected into every container to suppress tqdm progress
+# bar output. High-volume block-glyph writes (3-byte UTF-8: █▉▊▋▌▍▎▏) from
+# concurrent worker processes interleave at the OS level, producing torn
+# multi-byte sequences in the pod log stream that cause UnicodeDecodeError.
+# Components may override these by setting the same keys in their own env.
+_TQDM_SUPPRESS_ENV_VARS: dict[str, str] = {
+    "TQDM_DISABLE": "1",
+    "HF_DATASETS_DISABLE_PROGRESS_BARS": "1",
+}
+
 
 _T = typing.TypeVar("_T")
 
@@ -352,6 +362,10 @@ def get_output_path(output_name: str) -> str:
             k8s_client_lib.V1EnvVar(name=name, value=value)
             for name, value in (container_spec.env or {}).items()
         ]
+        user_env_names = {env.name for env in container_env}
+        for name, value in _TQDM_SUPPRESS_ENV_VARS.items():
+            if name not in user_env_names:
+                container_env.append(k8s_client_lib.V1EnvVar(name=name, value=value))
         main_container_spec = k8s_client_lib.V1Container(
             name=_MAIN_CONTAINER_NAME,
             image=container_spec.image,