Revert "update runc binary to 1.1.15"

This reverts commit 113a9f1.

runc 1.1.15 appears to have incresed chances for causing OOMs for
containers with small memory limits.  Revert the change in containerd
1.7 to unblock releases while the upstream runc issue is resolved.

Dependency-issue: opencontainers/runc#4427
Signed-off-by: Samuel Karp <samuelkarp@google.com>

script/setup/runc-version

@@ -1 +1 @@
-v1.1.15
+v1.1.14