bin/post_version.py: Pass version as an argument

I made a bad assumption; I assumed this would be run in the release
branch. But we don't do that, we run in the master branch. As a result
we need to pass the version as an argument.

Fixes: 3226b12a09
       ("release: Add an update_release_calendar.py script")
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Juan A. Suarez <jasuarez@igalia.com>

bin/post_version.py

@@ -21,6 +21,7 @@
 
 """Update the main page, release notes, and calendar."""
 
+import argparse
 import calendar
 import datetime
 import pathlib
@@ -51,18 +52,8 @@ def calculate_previous_version(version: str, is_point: bool) -> str:
     return '.'.join(base)
 
 
-def get_version() -> str:
-    v = pathlib.Path(__file__).parent.parent / 'VERSION'
-    with v.open('rt') as f:
-        raw_version = f.read().strip()
-    return raw_version.split('-')[0]
-
-
-def is_point_release() -> bool:
-    v = pathlib.Path(__file__).parent.parent / 'VERSION'
-    with v.open('rt') as f:
-        raw_version = f.read().strip()
-    return '-rc' not in raw_version
+def is_point_release(version: str) -> bool:
+    return not version.endswith('.0')
 
 
 def update_index(is_point: bool, version: str, previous_version: str) -> None:
@@ -110,11 +101,14 @@ def update_release_notes(previous_version: str) -> None:
 
 
 def main() -> None:
-    is_point = is_point_release()
-    version = get_version()
-    previous_version = calculate_previous_version(version, is_point)
+    parser = argparse.ArgumentParser()
+    parser.add_argument('version', help="The released version.")
+    args = parser.parse_args()
 
-    update_index(is_point, version, previous_version)
+    is_point = is_point_release(args.version)
+    previous_version = calculate_previous_version(args.version, is_point)
+
+    update_index(is_point, args.version, previous_version)
     update_release_notes(previous_version)