Unrolled build for #149721

Rollup merge of #149721 - generalmimon:rustc-book-sidebar-link-label-fix, r=ChrisDenton

rustc book: fix `*-pc-windows-msvc` link label in sidebar

As far as I know, `*-unknown-windows-msvc` is not a thing. At least if I search for "unknown-windows-msvc" in the entire [rust-lang](https://github.com/rust-lang) organization (https://github.com/search?q=org%3Arust-lang+%22unknown-windows-msvc%22++&type=code&state=open), it gives only this occurrence and 3 other occurrences in https://github.com/rust-lang/lld, which was archived in 2019.

I believe `*-pc-windows-msvc` is the correct replacement because that is the name of the page the link points to:

https://github.com/rust-lang/rust/blob/ba86c0460b0233319e01fd789a42a7276eade805/src/doc/rustc/src/platform-support/windows-msvc.md?plain=1#L1

Author: rust-timer

src/doc/rustc/src/SUMMARY.md

@@ -130,7 +130,7 @@
     - [\*-unknown-openbsd](platform-support/openbsd.md)
     - [\*-unknown-redox](platform-support/redox.md)
     - [\*-unknown-uefi](platform-support/unknown-uefi.md)
-    - [\*-unknown-windows-msvc](platform-support/windows-msvc.md)
+    - [\*-pc-windows-msvc](platform-support/windows-msvc.md)
     - [\*-uwp-windows-msvc](platform-support/uwp-windows-msvc.md)
     - [\*-wrs-vxworks](platform-support/vxworks.md)
     - [wasm32-wasip1](platform-support/wasm32-wasip1.md)