bin/gen_calendar_entries: fix newlines on windows

The documentation[1] for the csv module specifies that we should specify
newline='' when opening the output file. Without that, the module
garbles the newlines, writing them as \r\r\n on Windows instead of \r\n.

So let's do what the documentation says, and specify newline=''

[1]: https://docs.python.org/3/library/csv.html#id3

Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12405>

bin/gen_calendar_entries.py

@@ -105,7 +105,7 @@ def release_candidate(args: RCArguments) -> None:
 
     data = read_calendar()
 
-    with CALENDAR_CSV.open('w') as f:
+    with CALENDAR_CSV.open('w', newline='') as f:
         writer = csv.writer(f)
         writer.writerows(data)
 
@@ -147,7 +147,7 @@ def final_release(args: FinalArguments) -> None:
     data = read_calendar()
     date = _calculate_next_release_date(not args.zero_released)
 
-    with CALENDAR_CSV.open('w') as f:
+    with CALENDAR_CSV.open('w', newline='') as f:
         writer = csv.writer(f)
         writer.writerows(data)
 
@@ -199,7 +199,7 @@ def extend(args: ExtendArguments) -> None:
 
     current = read_calendar()
 
-    with CALENDAR_CSV.open('w') as f:
+    with CALENDAR_CSV.open('w', newline='') as f:
         writer = csv.writer(f)
         with write_existing(writer, current) as row:
             # Get rid of -rcX as well