BUG #18829: RAISE NOTICE appends 's' to string in PostgreSQL 17.2

The following bug has been logged on the website:

Bug reference: 18829
Logged by: Armand
Email address: armandnortjee(at)gmail(dot)com
PostgreSQL version: 17.2
Operating system: Windows 10
Description:

In PostgreSQL 17.2, when using the RAISE NOTICE command with a string
variable, the output incorrectly appends an extra 's' to the string value.
This issue does not occur when running the same code in earlier PostgreSQL
versions (e.g., PostgreSQL 16).

DO $$
DECLARE
my_var TEXT := 'garth';
BEGIN
RAISE NOTICE '%s is slim', my_var;
END
$$;

Expected Result:
The output should be:
NOTICE: garth is slim

Actual Result:
The output incorrectly shows:
NOTICE: garths is slim