lint: remove unneeded global statements

Author: mr-c

cwltool/main.py

@@ -119,7 +119,6 @@ def _terminate_processes() -> None:
     continuing to execute while it kills the processes that they've
     spawned. This may occasionally lead to unexpected behaviour.
     """
-    global docker_exe
     # It's possible that another thread will spawn a new task while
     # we're executing, so it's not safe to use a for loop here.
     while processes_to_kill:

cwltool/process.py

@@ -1109,7 +1109,6 @@ def __str__(self) -> str:
 
 def uniquename(stem: str, names: Optional[set[str]] = None) -> str:
     """Construct a thread-unique name using the given stem as a prefix."""
-    global _names
     if names is None:
         names = _names
     c = 1