[$] Development statistics for 6.19

Linus Torvalds released the 6.19 kernel on February 8, as expected. This development cycle brought 14,344 non-merge changesets into the mainline, making it the busiest release since 6.16 in July 2025. As usual, we have put together a set of statistics on where these changes come from, along with a quick look at how long new kernel developers stay around.