Update to redis 8, fixes #51

[bserem]

The Issue

• Fixes How to use Redis 8 with ddev-redis #51

Redis 7 is EOL. Most webservers are now ready to use Redis 8 (8.8+ actually).

How This PR Solves The Issue

Update ddev addon to use Redis 8

Manual Testing Instructions

ddev add-on get https://github.com/bserem/ddev-redis/tarball/redis8
ddev restart

[bserem]

I'm testing this internally, using Drupal, thought to push it so other people can also give it a spin and then we can update the addon.

Thanks

[stasadev]

Thank you!

Please also update the tests:

-export REDIS_MAJOR_VERSION=7
+export REDIS_MAJOR_VERSION=8

And let's replace Redis 6 with Redis 7 in:

ddev-redis/tests/test.bats

Lines 363 to 384 in b50ac77

	# bats test_tags=laravel-redis-6
	@test "Laravel installation: ddev redis-backend redis:6" {
	set -eu -o pipefail
	export REDIS_MAJOR_VERSION=6
	run ddev config --project-type=laravel --docroot=public
	assert_success
	laravel_redis_cache_setup
	echo "# ddev add-on get ${DIR} with project ${PROJNAME} in $(pwd)" >&3
	run ddev add-on get "${DIR}"
	assert_success
	run ddev redis-backend redis:${REDIS_MAJOR_VERSION}
	assert_success
	run ddev restart -y
	assert_success
	health_checks
	}