_content/doc/go1.24: use backticks for GOAUTH

For: golang/go#26232
For: golang/go#68545

Change-Id: I31fe54bee06a574dfce9335ac65f5d5b98fef756
Reviewed-on: https://go-review.googlesource.com/c/website/+/635340
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>

Author: danp

_content/doc/go1.24.md

@@ -66,7 +66,7 @@ a test integration system, you can revert to the text build output by setting
 
 <!-- go.dev/issue/26232 -->
 
-The new 'GOAUTH' environment variable provides a flexible way to authenticate
+The new `GOAUTH` environment variable provides a flexible way to authenticate
 with private modules. See `go help goauth` for more information.
 
 <!-- go.dev/issue/50603 -->