Add concurrency to the GitHub workflows to auto-cancel older runs of some actions in PRs.

[langleyd]

Within a particular PR we currently run actions for every commit. Some of these are very resource heavy like integration tests.
While we might want to run these for every commit on develop and main branches, within a PR we can probably afford to cancel jobs for all but the most recent commit.

For main and develop github.sha can be used in the group id to ensure every commit starts a job.
For feature branches github.ref in the group id to ensure all but the most recent job are cancelled.

Candidates for concurrency in PR branches are:

• Integration test
• Unit tests
• GPlay/FDriod Builds
• Quality checks

Example on element-ios -> element-hq/element-ios#5101

Documentation on concurrency -> https://docs.github.com/en/actions/using-jobs/using-concurrency