Enable multi-generation LRU by default in Talos 1.5

[nberlee]

The PR #710 introduced multi-gen LRU support, although it is currently not activated by default.

Since the release of Talos 1.4.1, I have configured most of my clusters to use multi-gen LRU using the following configuration:

        sysfs:
            kernel.mm.lru_gen.enabled: y

This change has brought about noticeable benefits, such as a significant decrease in OOMkills, without any apparent drawbacks. I have been running multi-gen LRU in most clusters for more than 2 months. Considering that several other mainstream general-purpose Linux distributions have started enabling LRU, I suggest that we enable multi-gen LRU by default in the upcoming Talos 1.5 release.