_content/blog: fix typo in execution traces 2024 post

Change-Id: Ida1ac5b41924f863f0b443ad874ed6a43730f4f4
Reviewed-on: https://go-review.googlesource.com/c/website/+/571677
Reviewed-by: Ian Lance Taylor <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>
Commit-Queue: Ian Lance Taylor <[email protected]>
Auto-Submit: Michael Knyszek <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: mknyszek

_content/blog/execution-traces-2024.md

@@ -54,7 +54,7 @@ applications, which limits tracing to situational usage, rather than continuous
 profiling.
 It turned out that much of the cost of tracing came down to tracebacks.
 Many events produced by the runtime have stack traces attached, which are invaluable to actually
-identifying what goroutines where doing at key moments in their execution.
+identifying what goroutines were doing at key moments in their execution.
 
 Thanks to work by Felix Geisendörfer and Nick Ripley on optimizing the efficiency of tracebacks,
 the run-time CPU overhead of execution traces has been cut dramatically, down to 1–2% for many