pyupgrade: drop redundant `open()` modes On one hand, this gets rid of some py2 cruft (like `U` and `t` modes). OTOH, I like being explict. But there's no way to disable individual transformations (and this change is part of `_fix_tokens()`, which is even harder to selectively use locally), and I'd rather have less noise when using `pyupgrade`. Warning: `contrib/synthrepo.py` appears not to have been updated to py3, as it's passing str to `error.Abort`. But since it was opening the file in unicode on py2, this change is a no-op.

--- a/contrib/synthrepo.py	Mon Jan 06 01:44:46 2025 -0500
+++ b/contrib/synthrepo.py	Tue Jan 07 17:28:46 2025 -0500
@@ -326,7 +326,7 @@
 
     dictfile = opts.get('dict') or '/usr/share/dict/words'
     try:
-        fp = open(dictfile, 'rU')
+        fp = open(dictfile)
     except OSError as err:
         raise error.Abort('%s: %s' % (dictfile, err.strerror))
     words = fp.read().splitlines()