chore: Add automation for stale issues and PRs

[jaydeluca]

Based on the automation used in the otel java projects, but with longer thresholds

[Copilot]

Pull request overview

Adds a scheduled GitHub Actions workflow to automatically mark inactive PRs/issues as stale and close them after additional inactivity, using actions/stale with longer thresholds aligned to the referenced otel-java setup.

Changes:

• Introduce an hourly scheduled workflow to stale/close PRs after 120 + 30 days of inactivity.
• Introduce an hourly scheduled workflow to stale/close issues after 360 + 30 days of inactivity.
• Configure required job-level permissions for actions/stale.

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[jaydeluca]

I am once again unable to get linting to work locally to see what the issue is, and the CI output isnt helpful, i'll return to this later

when i run mise run format locally i am getting

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.542 s
[INFO] Finished at: 2026-03-02T08:51:43-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] No plugin found for prefix 'spotless' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/jay/.m2/repository), central (https://repo.maven.apache.org/maven2)] -> [Help 1]

[zeitlinger]

when i run mise run format locally i am getting

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.542 s
[INFO] Finished at: 2026-03-02T08:51:43-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] No plugin found for prefix 'spotless' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/jay/.m2/repository), central (https://repo.maven.apache.org/maven2)] -> [Help 1]

created #1931 for that

[zeitlinger]

CI lint failure is a Prettier formatting issue on the workflow YAML.

Fix: mise run fix, then verify with mise run lint.

(I know the CI output doesn't make this obvious — filed flint#89 to add a hint to the failure output.)

[zeitlinger]

LGTM! Clean setup, good separation of PR vs issue timelines. One minor thought: hourly cron (23 * * * *) seems frequent for a stale bot — daily (e.g. 23 6 * * *) would work just as well and save CI minutes. But not a blocker.

Heads up: lint CI is failing — please fix before merge.