Turbopack: patch sourcemap crate (#82641)

The source content was somethings incorrect with scope hoisting on Turbopack:

<img width="2018" height="721" alt="image" src="https://github.com/user-attachments/assets/e2e1bf1c-2a84-4acb-8388-a809670b4902" />

Fix is in swc-project/swc-sourcemap#7

Author: mischnic

Cargo.lock

@@ -450,3 +450,4 @@ hyper = { git = "https://github.com/bgw/hyper-rs.git", branch = "v1.6.0-with-mac
 mdxjs = { git = "https://github.com/mischnic/mdxjs-rs.git", branch = "swc-core-32" }
 lightningcss = { git = "https://github.com/parcel-bundler/lightningcss.git", branch = "mischnic/bump-browserslist" }
 parcel_selectors = { git = "https://github.com/parcel-bundler/lightningcss.git", branch = "mischnic/bump-browserslist" }
+swc_sourcemap = { git = "https://github.com/mischnic/rust-sourcemap.git", branch = "mischnic/source-content-mixup" }