CI/CD: Cancel concurrent workflow runs

[ThisIsMissEm]

Summary

This prevents multiple pushes from blocking up the workflow runner queue

Related Issue

No related issue to my knowledge, observed during #434

Changes

List the specific modifications made in this PR.
Focus on what was changed without going into detail about impact.

• Uses the workflow concurrency controls to cancel prior workflow runs automatically.

Benefits

This improves the performance of the workflow runners by reducing their workload when people push multiple commits in quick succession to a branch.

Checklist

• Did you add a changelog entry to the CHANGES.md?
• Did you write some relevant docs about this change (if it's a new feature)?
• Did you write a regression test to reproduce the bug (if it's a bug fix)?
• Did you write some tests for this change (if it's a new feature)?
• Did you run deno task test-all on your machine?

Additional Notes

Docs: https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#concurrency

[gemini-code-assist]

Note

Gemini is unable to generate a summary for this pull request due to the file types involved not being currently supported.

[dahlia]

Thanks!

[github-actions]

The latest push to this pull request has been published to JSR and npm as a pre-release:

Package	Version	JSR	npm
@fedify/fedify	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/cli	1.9.0-pr.442.1663+081fe35e	JSR
@fedify/amqp	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/cfworkers	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/denokv	1.9.0-pr.442.1663+081fe35e	JSR
@fedify/elysia	1.9.0-pr.442.1663+081fe35e		npm
@fedify/express	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/h3	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/hono	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/nestjs	1.9.0-pr.442.1663+081fe35e		npm
@fedify/next	1.9.0-pr.442.1663+081fe35e		npm
@fedify/postgres	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/redis	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/sqlite	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/sveltekit	1.9.0-pr.442.1663+081fe35e	JSR	npm
@fedify/testing	1.9.0-pr.442.1663+081fe35e	JSR	npm

[github-actions]

The docs for this pull request have been published:

https://d319fb66.fedify.pages.dev