fix: be more graceful when MS tool moves files underneath us

It moves temporary files into their final place, and that might happen
as we are trying to get the file size - so handle that exception.

.pre-commit-config.yaml

@@ -9,4 +9,4 @@ repos:
         # supported by your project here, or alternatively use
         # pre-commit's default_language_version, see
         # https://pre-commit.com/#top_level-default_language_version
-        language_version: python3.11
+        language_version: python3.12

cumulus_etl/deid/mstool.py

@@ -80,6 +80,17 @@ def _compare_file_sizes(target: dict[str, int], current: dict[str, int]) -> floa
     return total_current / total_expected
 
 
+def _get_file_size_safe(path: str) -> int:
+    try:
+        return os.path.getsize(path)
+    except FileNotFoundError:
+        # The MS Tool moves temporary files around as it completes each file,
+        # so we guard against an unlucky race condition of a file being moved
+        # before we can query its size. (Total size will be wrong for a moment,
+        # but it will correct itself in a second.)
+        return 0
+
+
 def _count_file_sizes(pattern: str) -> dict[str, int]:
     """Returns all files that match the given pattern and their sizes"""
-    return {os.path.basename(filename): os.path.getsize(filename) for filename in glob.glob(pattern)}
+    return {os.path.basename(filename): _get_file_size_safe(filename) for filename in glob.glob(pattern)}