Don't mention explicit publication deadline of LOOPS book 2

Change the publication deadline of LOOPS book 2 from an explicit timeframe to just "forthcoming".

Signed-off-by: Paolo Amoroso <info@paoloamoroso.com>

Author: pamoroso

content/en/software/using-medley/_index.md

@@ -82,6 +82,6 @@ These documents were converted from Medley's internal format into PDFs. Watch ou
 - [Interlisp Reference Manual (1993)](/documentation/IRM.pdf)
 - Medley LOOPS Books (LOOPS, the Lisp Object-Oriented Programming System, was an object extension of Interlisp):
   - [Volume I: Medley LOOPS: The Basic System](/documentation/2024-loops-book-1.pdf)
-  - Volume II: Medley LOOPS: Tools and Utilities (coming in the second half of 2025)
+  - Volume II: Medley LOOPS: Tools and Utilities (forthcoming)
   - Volume III: Medley LOOPS: Rule-based Systems and the Truckin Game (coming in the fall of 2025)