Updates for 2026-Jan-01 part2 (#709)

* Move optional steps for testing VMs out of README.md file
This may help avoid new users being confused that they must follow
those instructions.

Signed-off-by: Andy Fingerhut <andy_fingerhut@alum.wustl.edu>

* Add 2025-Jan-30 versions of source code for install.sh

Signed-off-by: Andy Fingerhut <andy_fingerhut@alum.wustl.edu>

* Make install.sh default to installing 2026-Jan-01 version

Signed-off-by: Andy Fingerhut <andy_fingerhut@alum.wustl.edu>

---------

Signed-off-by: Andy Fingerhut <andy_fingerhut@alum.wustl.edu>

Author: jafingerhut

vm-ubuntu-24.04/install.sh

@@ -35,7 +35,7 @@ print_usage() {
 
 if [ $# -eq 0 ]
 then
-    VERSION="2025-Oct-01"
+    VERSION="2026-Jan-01"
     echo "No version specified.  Defaulting to ${VERSION}"
 elif [ $# -eq 1 ]
 then