Use reusable workflows for CI jobs

[szokeasaurusrex]

The Ruby SDK cleaned up their CI flow by using reusable workflows: @neel.shah said:

btw probably interesting for everyone, @peter made the ruby CI really clean by creating a job dependency flow
it looks like this

https://github.com/getsentry/sentry-ruby/actions/runs/15043844757
the main file is this
https://github.com/getsentry/sentry-ruby/blob/master/.github/workflows/tests.yml
that invokes each specific test matrix
https://github.com/getsentry/sentry-ruby/blob/master/.github/workflows/sentry_ruby_test.yml

We could implement something similar in Sentry CLI, with tests and lints each in one job (with subjobs for each OS)