[ci] Move cpp-tests job inside Pulsar CI workflow

[nicoloboschi]

Motivation

There are multiple benefits to adding the cpp-tests inside the main workflow:

• Now CPP tests runner is triggered even for docs-only changes
• The build artifacts are not reused
• CPP tests can be skipped in case of integration-tests failures or build broken or checkstyle errors etc.
• Less workflows

Modifications

• Moved the job right after the integration-tests
• Now maven artifacts are reused from the previous job
• Added dependency to the new job for the latest step Pulsar CI checks completed
• Removed cpp-tests from the required checks because now it's included in Pulsar CI checks completed

• doc-not-needed

[lhotari]

LGTM

[tisonkun]

BTW, this PR triggers only part of CI tasks. I may assume that a change in pulsar-ci.yml should trigger almost full test cases?

[tisonkun]

It seems that we still take a long time to complete CI. For example, 10f7209 made 11 hours ago and now it's not completed.

[lhotari]

It's better to add a name for the build job so that it looks consistent in the UI.

[tisonkun]

Thank you!