[llvm] [llvm-lit] Resolve env subcommand required error (PR #98414)

[James Henderson via llvm-commits]

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@@ -743,7 +743,10 @@ def _executeShCmd(cmd, shenv, results, timeoutHelper):
                     cmd_shenv = ShellEnvironment(shenv.cwd, shenv.env)
                 args = updateEnv(cmd_shenv, args)
                 if not args:
-                    raise InternalShellError(j, "Error: 'env' requires a" " subcommand")
+                    # Return the environment variables if no argument is provided 
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jh7370 wrote:

```suggestion
                    # Return the environment variables if no argument is provided.
```
Trailing whitespace.

Also, please make sure all your python files are formatted with darker.

https://github.com/llvm/llvm-project/pull/98414