main/haproxy: backport LTS version from edge and upgrade to 2.2.2

add note to use only LTS versions

take maintainership according to Natanael Copa ask on #alpine-devel IRC
channel
7 jobs for !10937 with 3.12-stable-haproxy-2.2.2 in 4 minutes and 18 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Lint
passed #177137
docker-alpine x86_64
lint

00:00:25

 
  Build
passed #177142
docker-alpine ci-build aarch64
build-aarch64

00:02:36

passed #177143
docker-alpine ci-build armv7
build-armv7

00:01:56

passed #177141
docker-alpine ci-build ppc64le
build-ppc64le

00:02:13

passed #177140
docker-alpine ci-build s390x
build-s390x

00:01:15

passed #177139
docker-alpine ci-build x86
build-x86

00:01:18

passed #177138
docker-alpine ci-build x86_64
build-x86_64

00:01:09