Update content/inside-rust/infrastructure-team-2025-q3-recap-and-q4-plan.md

Co-authored-by: Jakub Beránek <[email protected]>

Author: marcoieni

content/inside-rust/infrastructure-team-2025-q3-recap-and-q4-plan.md

@@ -83,7 +83,9 @@ Until now, CI only had jobs that ran on PRs or when a merge to the default branc
 We added support for CI jobs that run only on demand, allowing contributors to run these tests on PRs whenever they are concerned about breaking certain parts of the codebase. This is useful for testing tier 2 and tier 3 targets in CI, whose tests don’t always run on CI by default.
 
 This feature was requested in [\#t-infra \> Testing for T2/T3 targets](https://rust-lang.zulipchat.com/#narrow/channel/242791-t-infra/topic/Testing.20for.20T2.2FT3.20targets/with/526715751) and documented in [rust-lang/rust#143283](https://github.com/rust-lang/rust/pull/143283).
+### Automating subtree synchronization
 
+We have implemented a new tool called [`rustc-josh-sync`](https://github.com/rust-lang/josh-sync), which makes it easier to synchronize changes between [Josh](https://josh-project.github.io/josh/intro.html) subtrees and the main `rust-lang/rust` repository. We have migrated the existing Josh subtrees (such as `miri` or `rust-analyzer`) to this tool, which enables us to perform subtree synchronizations in a more unified way.
 ### Repository default branch renames
 
 We're updating our repositories to use more inclusive naming conventions. This quarter, we renamed the default branches from `master` to `main` in the [`rustc-dev-guide`](https://github.com/rust-lang/rustc-dev-guide) ([PR](https://github.com/rust-lang/rustc-dev-guide/pull/2570)), [`www.rust-lang.org`](https://github.com/rust-lang/www.rust-lang.org) ([PR](https://github.com/rust-lang/www.rust-lang.org/pull/2205)) and [`blog.rust-lang.org`](https://github.com/rust-lang/blog.rust-lang.org) ([PR](https://github.com/rust-lang/blog.rust-lang.org/pull/1689/)) repositories.