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)
latest detached
Status Job ID Name Coverage
  Lint
passed #177137
x86_64 docker-alpine
lint

00:00:25

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

00:02:36

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

00:01:56

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

00:02:13

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

00:01:15

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

00:01:18

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

00:01:09