Protect against decoding errors with subprocess text mode

All these are calling subprocess in 'text mode', where it will
try to decode stdout/stderr using the default encoding (utf-8
for us). If it doesn't decode, subprocess will raise an exception
and kobo doesn't handle it, it just passes it along to us, so
things blow up - see https://pagure.io/releng/issue/12474 . To
avoid this, let's set `errors="replace"`, which tells the decoder
to replace invalid data with ? characters. This way we should get
as much of the output as can be read, and no crashes.

We also replace `universal_newlines=True` with `text=True` as
the latter is shorter, clearer, and what Python 3 subprocess
wants us to use, it considers `universal_newlines` to just be
a backwards-compatibility thing - "The universal_newlines argument
is equivalent to text and is provided for backwards compatibility"

Signed-off-by: Adam Williamson <awilliam@redhat.com>
Merges: https://pagure.io/pungi/pull-request/1812

pungi/ostree/tree.py

@@ -64,7 +64,8 @@ class Tree(OSTree):
                 show_cmd=True,
                 stdout=True,
                 logfile=log_file,
-                universal_newlines=True,
+                text=True,
+                errors="replace",
             )
         finally:
             os.umask(oldumask)
@@ -77,7 +78,8 @@ class Tree(OSTree):
             show_cmd=True,
             stdout=True,
             logfile=log_file,
-            universal_newlines=True,
+            text=True,
+            errors="replace",
         )
 
     def _update_ref(self):