Use "with suppress()" to suppress python exceptions

Using
```Python
with suppress(OSError):
    os.remove('somefile.tmp')
```
instead of
```Python
try:
    os.remove('somefile.tmp')
except OSError:
    pass
```
makes the code more compact and more readable IMO.

This pattern was recommended by Raymond Hettinger, a Python Core
Developer in his talk "Transforming Code into Beautiful, Idiomatic Python" at https://www.youtube.com/watch?v=OSGv2VnC0go. The transcript is available at https://github.com/JeffPaine/beautiful_idiomatic_python

kittens/diff/main.py

@@ -9,6 +9,7 @@ import warnings
 from collections import defaultdict
 from functools import partial
 from gettext import gettext as _
+from contextlib import suppress
 
 from kitty.cli import CONFIG_HELP, parse_args
 from kitty.constants import appname
@@ -511,10 +512,8 @@ usage = 'file_or_directory_left file_or_directory_right'
 
 def terminate_processes(processes):
     for pid in processes:
-        try:
+        with suppress(Exception):
             os.kill(pid, signal.SIGKILL)
-        except Exception:
-            pass
 
 
 def main(args):