Changes:
- The `Why?` link is updated from `why` to `why-gitlab`.
- The `Is it any good?` link was already redirecting to `why-gitlab`,
so that section is moved to `Why?`.
- The `Is it awesome?` link is 9 years old:
(c3007888). It may be the time to
make this change.

Since Redis 5 already reached EOL, let's drop support for it.

Changelog: changed

On 2023-03-07, GitLab.com will be updated to use Ruby 3. this commit
updaets the software stack section on the README file to account for
that.

Related to https://gitlab.com/gitlab-com/gl-infra/production/-/issues/5494

https://codechallenge.dev/j/kubeconeu

Gitaly is about to bump the minimum required Git version to v2.33.0 to
make use of several features introduced since the current miminum
required version, which is v2.31.0. Adapt the system check to verify
we've got a recent-enough version of Git.

Changelog: changed

https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/config/puma.rb.example.development
does not exitst on 'master'.

See https://gitlab.com/gitlab-org/gitlab/-/blob/master/config/puma.example.development.rb

Changelog: changed

That were listing PG11

Updates docs related to Unicorn support removal.

Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

I found the redirected link based
on 34ceed33

Our markdown processor do not allow embedding videos.

Since Ruby 2.7.2 comes with bundler v2.1.4 by default, we need to
upgrade the Gemfile.lock and bump the CI cache keys. We also need to
install bundler v1.17.3 to ensure a smooth transition for other
dependencies, like Gitaly.

Exclude development gems from QA bundle install since debaser doesn't
compile on Ruby 2.7.

Fixes https://gitlab.com/gitlab-org/gitlab-workhorse/-/issues/268

via graphicsmagick

cf.
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/38475
https://gitlab.com/gitlab-org/gitlab/-/issues/213749
https://gitlab.com/gitlab-org/gitlab/-/issues/213174



Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>