google-calendar: Improve CLIENT_SECRET_FILE occurrences.

Removed it from google-calendar script, as it is only used for the first
run authorization by get-google-credentials.

Edited a comment clarifying its purpose in get-google-credentials.

Author: Niloth-p

zulip/integrations/google/get-google-credentials

@@ -11,8 +11,9 @@ SCOPES = ["https://www.googleapis.com/auth/calendar.events.readonly"]
 # File containing user's access and refresh tokens for Google application requests.
 # If it does not exist, e.g., first run, it is generated on user authorization.
 TOKENS_FILE = "google-tokens.json"
-# This file contains the information that google uses to figure out which application is requesting
-# this client's data.
+# The client secret file identifies the application requesting the client's data,
+# and is required for the OAuth flow to fetch the tokens.
+# It needs to be downloaded from Google, by the user.
 CLIENT_SECRET_FILE = "client_secret.json"  # noqa: S105
 HOME_DIR = os.path.expanduser("~")
 

zulip/integrations/google/google-calendar

@@ -18,7 +18,6 @@ SCOPES = ["https://www.googleapis.com/auth/calendar.events.readonly"]
 # File containing user's access and refresh tokens for Google application requests.
 # If it does not exist, e.g., first run, it is generated on user authorization.
 TOKENS_FILE = "google-tokens.json"
-CLIENT_SECRET_FILE = "client_secret.json"  # noqa: S105
 HOME_DIR = os.path.expanduser("~")
 
 # Our cached view of the calendar, updated periodically.