Reduce duplication in CI using composite actions

[tannalynn]

Update CI to use composite actions to reduce how much duplication we have going on

kaylas comment

Seeing all the duplication, I wonder if we could use a composite action to reduce some of the steps we write again and again?

Here's the GHA doc on reducing duplication that taught me about this concept.

Rather than push things up into a separate repo, I imagine we could just use our actions directory.

[workato-integration[bot]]

https://new-relic.atlassian.net/browse/NR-358863

[tannalynn]

https://github.com/newrelic/newrelic-ruby-agent/pull/3210