doc: fix url to profile.ts source (#10628)

This PR fixes a broken link to the firefox profile definitions in one of
the comments.

The `profile.js` file was renamed to `profile.ts` while the rest of the
url remained the same.

Author: ydewit

src/Lean/Util/Profiler.lean

@@ -14,7 +14,7 @@ public section
 
 namespace Lean.Firefox
 
-/-! Definitions from https://github.com/firefox-devtools/profiler/blob/main/src/types/profile.js -/
+/-! Definitions from https://github.com/firefox-devtools/profiler/blob/main/src/types/profile.ts -/
 
 structure Milliseconds where
   ms : Float