Fold list of merged pull requests

It is quite long and noisy, and IMO not *that* interesting to most readers.

Author: Kobzol

draft/DRAFT_TEMPLATE

@@ -104,13 +104,18 @@ Are you a new or experienced speaker looking for a place to share something cool
 
 If you are an event organizer hoping to expand the reach of your event, please submit a link to the website through a [PR to TWiR](https://github.com/rust-lang/this-week-in-rust) or by reaching out on [X (formerly Twitter)](https://x.com/ThisWeekInRust) or [Mastodon](https://mastodon.social/@thisweekinrust)!
 
+### Rust Compiler Performance Triage
+
+<!-- Perf results go here -->
+
 ## Updates from the Rust Project
 
-<!-- Rust updates go here -->
+<details>
+<summary>Merged pull requests in the Rust toolchain</summary>
 
-### Rust Compiler Performance Triage
+<!-- Rust updates go here -->
 
-<!-- Perf results go here -->
+</details>
 
 ### [Approved RFCs](https://github.com/rust-lang/rfcs/commits/master)