Use Linux 6.12 in build-many-glibcs.py

[Joseph Myers]

Tested with build-many-glibcs.py (host-libraries, compilers and glibcs
builds).

diff --git a/scripts/build-many-glibcs.py b/scripts/build-many-glibcs.py
index a5f97662c3..c53aa8964c 100755
--- a/scripts/build-many-glibcs.py
+++ b/scripts/build-many-glibcs.py
@@ -828,7 +828,7 @@ class Context(object):
                             'gcc': 'vcs-13',
                             'glibc': 'vcs-mainline',
                             'gmp': '6.3.0',
-                            'linux': '6.11',
+                            'linux': '6.12',
                             'mpc': '1.3.1',
                             'mpfr': '4.2.1',
                             'mig': 'vcs-mainline',

-- 
Joseph S. Myers
josmyers@redhat.com