Fix rustup run command in the 1.64 blog post

pietroalbini · web-flow · commit 71dbed4fd6d4 · 2022-09-22T15:55:37.000+02:00
diff --git a/posts/2022-09-22-Rust-1.64.0.md b/posts/2022-09-22-Rust-1.64.0.md
@@ -157,7 +157,7 @@ At this time, to run the rustup-installed version, you need to invoke it this
 way:
 
 ```
-rustup run rust-analyzer
+rustup run stable rust-analyzer
 ```
 
 The next release of rustup will provide a built-in proxy so that running the
