Fixing typo in py_unittest breaking deployments (#4612)

This fixes the following error:

```
  File "/usr/local/google/home/metzman/clusterfuzz-311/butler.py", line 421, in <module>                                                                                                                           
    sys.exit(main())                                                                                                                                                                                               
             ^^^^^^                                                                                                                                                                                                
  File "/usr/local/google/home/metzman/clusterfuzz-311/butler.py", line 407, in main                                                                                                                               
    return command.execute(args)                                                                                                                                                                                   
           ^^^^^^^^^^^^^^^^^^^^^                                                                                                                                                                                   
  File "/usr/local/google/home/metzman/clusterfuzz-311/src/local/butler/deploy.py", line 576, in execute                                                                                                           
    package.package(                                                                                                                                                                                               
  File "/usr/local/google/home/metzman/clusterfuzz-311/src/local/butler/package.py", line 87, in package
    py_unittest.execute(args={})                                                                                                                                                                                   
  File "/usr/local/google/home/metzman/clusterfuzz-311/src/local/butler/py_unittest.py", line 299, in execute                                 
    target=args.target,                                                                                                                                                                                            
           ^^^^^^^^^^^
AttributeError: 'dict' object has no attribute 'target'
```

Author: vitorguidi

src/local/butler/package.py

@@ -21,7 +21,6 @@
 from local.butler import appengine
 from local.butler import common
 from local.butler import constants
-from local.butler import py_unittest
 from src.clusterfuzz._internal.base import utils
 
 MIN_SUPPORTED_NODEJS_VERSION = 4
@@ -84,8 +83,6 @@ def package(revision,
     print('You do not have nodejs, or your nodejs is not at least version 4.')
     sys.exit(1)
 
-  py_unittest.execute(args={})
-
   common.install_dependencies(platform_name=platform_name)
 
   # This needs to be done before packaging step to let src/appengine/config be