Use Linux 6.18 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 f74c6414e7..d9f38ba070 100755
--- a/scripts/build-many-glibcs.py
+++ b/scripts/build-many-glibcs.py
@@ -865,7 +865,7 @@ class Context(object):
                             'gcc': 'vcs-15',
                             'glibc': 'vcs-mainline',
                             'gmp': '6.3.0',
-                            'linux': '6.17',
+                            'linux': '6.18',
                             'mpc': '1.3.1',
                             'mpfr': '4.2.2',
                             'mig': 'vcs-mainline',

-- 
Joseph S. Myers
josmyers@redhat.com