env: track DVC_IGNORE_ISATTY as a env that we support (#6202)

dvc/env.py

@@ -6,3 +6,4 @@ DVCLIVE_PATH = "DVCLIVE_PATH"
 DVCLIVE_SUMMARY = "DVCLIVE_SUMMARY"
 DVCLIVE_HTML = "DVCLIVE_HTML"
 DVCLIVE_RESUME = "DVCLIVE_RESUME"
+DVC_IGNORE_ISATTY = "DVC_IGNORE_ISATTY"

dvc/progress.py

@@ -6,6 +6,7 @@ from threading import RLock
 
 from tqdm import tqdm
 
+from dvc.env import DVC_IGNORE_ISATTY
 from dvc.utils import env2bool
 
 logger = logging.getLogger(__name__)
@@ -77,7 +78,7 @@ class Tqdm(tqdm):
         # auto-disable based on TTY
         if (
             not disable
-            and not env2bool("DVC_IGNORE_ISATTY")
+            and not env2bool(DVC_IGNORE_ISATTY)
             and hasattr(file, "isatty")
         ):
             disable = not file.isatty()