note python threading changes

Author: acmorrow

CHANGES.txt

@@ -60,6 +60,11 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
     - The NewParallel scheduler is now the default, the `tm_v2` flag is removed,
       and the old scheduler is opt-in under `--experimental=legacy_sched`. Additionally,
       the new scheduler is now used for -j1 builds as well.
+    - A python interpreter with support for the `threading` package is now required,
+      and this is enforced on startup. SCons currently sets its minimum supported
+      Python to 3.6, and it was not until Python 3.7 where `threading` became
+      default supported. In practice, we expect most real world Python 3.6 deployments
+      will have `threading` support enabled, so this will not be an issue.
 
   From Mats Wichmann:
     - Add support for Python 3.13 (as of alpha 2). So far only affects

RELEASE.txt

@@ -33,6 +33,7 @@ CHANGED/ENHANCED EXISTING FUNCTIONALITY
   that the generated function argument list matches the function's
   prototype when including a header file. Fixes GH Issue #4320
 - Now supports pre-release Python 3.13
+- Support for Python versions without support for the `threading` package has been removed
 
 FIXES
 -----